Do not block system messages when block_unsubscribed is set
This was broken in 0.10.0 when switching to LM.
Reported by roughnecks in the MUC room, issue spotted by Hermitifier.
syntax: glob
Makefile
Makefile.in
*.[oa]
*.l[oa]
.libs
.deps
mcabber/mcabber/hgcset.h
mcabber/mcabber/mcabber
mcabber/mcabber/mcabber.exe
mcabber/mcabber.pc
autom4te.cache
mcabber/aclocal.m4
mcabber/configure
mcabber/depcomp
mcabber/libtool
mcabber/ltmain.sh
mcabber/macros/lt*.m4
mcabber/macros/libtool.m4
mcabber/missing
mcabber/mkinstalldirs
mcabber/mcabber/stamp-h1
mcabber/include/stamp-h2
config.h*
config.{log,cache,guess,status,sub}
mcabber/doc/guide/guide.{aux,bbl,blg,log,out,pdf,toc}
*.sw?
cscope.out
tags
mcabber/ptodo
mcabber/ppatches