core: replaced gtk3reactor by gireactor

twisted/plugins/sat_plugin.py

@@ -40,8 +40,8 @@ from sat.core.i18n import _
 
 def initialise(options):
     """Method to initialise global modules"""
-    from twisted.internet import gtk3reactor
-    gtk3reactor.install()
+    from twisted.internet import gireactor
+    gireactor.install()
     # XXX: We need to configure logs before any log method is used, so here is the best place.
     from sat.core import log_config
     log_config.satConfigure(C.LOG_BACKEND_TWISTED, C, backend_data=options)