Revert "Jenkins' lo_tb_master_linux needs --disable-werror too"

This reverts commit 7990bfd3, which is no longer
needed, see 5ae3f1fb "Re-enable --enable-werror
for Jenkins' gerrit_linux_gcc_release job".

Conflicts:
	distro-configs/Jenkins/Linux_rel_master.conf

Change-Id: I90725ecbef0e0cbd908c3d4d9e87ab2336f567c5

distro-configs/Jenkins/Linux_rel_master.conf

---disable-werror
 --enable-kde5
 CC=/opt/rh/devtoolset-7/root/usr/bin/gcc
 CXX=/opt/rh/devtoolset-7/root/usr/bin/g++