plugins/evolution: Fixes for several crashes in the plugin
plugins/evolution: Fixes for several crashes in the plugin

More information here:
https://bugzilla.gnome.org/show_bug.cgi?id=644695#c17

hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,hoheinzollern/tracker