bug in missionname function for some dummy missions

a dummy mission might not contain check.sh, init.sh or static.sh, but
only a gshrc file

Author: PH

scripts/missionname

@@ -17,17 +17,17 @@ missionname() {
     cd "$path"
   fi
 
+  # look for the enclosing mission directory
   while true
   do
     [ -f check.sh ] && break
     [ -f static.sh ] && break
     [ -f init.sh ] && break
+    [ -f gshrc ] && break
     [ "$(pwd -P)" = "/" ] && break
     cd ..
   done
 
-
-
   case "$PWD" in
     "$GSH_MISSIONS/"*)
       path=$(pwd -P)