build: Switch back to DISTCHECK_CONFIGURE_FLAGS
Switch back to using DISTCHECK_CONFIGURE_FLAGS instead of the
AM_-version in Makefile.am, as the latter is not supported by Automake
version in RHEL6.
Instead, use a special variable AUX_DISTCHECK_CONFIGURE_FLAGS to
augment distcheck target configure flags from the command line.
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
(cherry picked from commit c6e39e15178675d0779e0ae855245774a09b4eb5)
Conflicts:
Makefile.am