contrib/rpm: disable --with-more-asserts for devel-builds

The NetworkManager spec file used to determine devel builds as those that
have an odd minor version number. In that case, the built package would
enable more-asserts.
-- By the way, why is '1.13.3-dev' considered a delopment version worthy of more
asserts, but a build from the development phase of the next minor release on
'nm-1-12' branch not?

Note that during the development phase of Fedora (and sometimes even afterwards),
we commonly package development versions from 'master'. For example '1.12.0-0.1',
which is some snapshot with version number '1.11.x-dev' (or '1.12-rc1' in this case),
but before the actual '1.12.0' release.

It's problematic that for part of the devel phase we compile the
package for the distribution with more assertions. This package is
significanly different and rpmdiff and coverity give different results
for them.
For example, the binary size of debug packages is larger, so first
rpmdiff will complain that the binary sized increased (compare to the
previous version) and then later it decreases again.
Likewise, coverity finds significantly different issues on a debug
build. For example, it sees assertions against NULL and takes that
as a hint as to whether the parameter can/shall be NULL. Keeping
coverity warnings low is already high effort to sort out false
positives. We should not invest time in checking debug builds with
coverity, at least not as long as there are more important issues.

But more importantly, the --with-more-asserts configure option governs whether
nm_assert() is enabled. The only point of existance of nm_assert() -- compared to
g_assert(), g_return_*() and assert() -- is that this variant is disabled by default.
It's only used for checks that are really really not supposed to fail and/or
which may be expensive to do. This is useful for developing and CI,
but it's not right to put into the distribution. It really enables
assertions that you don't want in such a scenario. Enabling them even
for distribution builds defeats their purpose. If you care about an
assertion to be usually/always enabled, you should use g_assert() or
g_return_*() instead.

What this changes, that "devel" builds in koji/brew do not have more-asserts
enabled. When manually building the SRPM one still can enable it,
for example via

  $ ./contrib/fedora/rpm/build_clean.sh -w debug

Also our CI has an option to build packages with or without more-asserts
(defaulting to more asserts already).

contrib/fedora/rpm/NetworkManager.spec

@@ -43,8 +43,6 @@
 
 %global real_version_major %(printf '%s' '%{real_version}' | sed -n 's/^\\([1-9][0-9]*\\.[1-9][0-9]*\\)\\.[1-9][0-9]*$/\\1/p')
 
-%global is_devel_build %(printf '%s' '%{real_version}' | sed -n 's/^1\\.\\([0-9]*[13579]\\)\\..*/1/p')
-
 ###############################################################################
 
 %bcond_without adsl
@@ -57,11 +55,7 @@
 %bcond_without ppp
 %bcond_without nmtui
 %bcond_without regen_docs
-%if 0%{is_devel_build}
-%bcond_without debug
-%else
 %bcond_with    debug
-%endif
 %bcond_without test
 %bcond_with    sanitizer
 %if 0%{?fedora} > 28 || 0%{?rhel} > 7