Define RECHECK_LOGS and TEST_EXTENSIONS outside of the UNIT_TESTS
conditional
Fixes the following warnings:
/usr/share/automake-1.14/am/check.am: warning: RECHECK_LOGS was already defined in condition UNIT_TESTS, which is included in condition TRUE ...
modules/remotebackend/Makefile.am:74: ... 'RECHECK_LOGS' previously defined here
modules/remotebackend/Makefile.am:62: warning: 'TEST_EXTENSIONS' cannot have conditional contents