gpull: check for severy remote branch case

bin/gpull

@@ -71,6 +71,9 @@ pull_from_unique_branch()
 {
         [ -n "$REPO" ] || return
         REMOTEBRANCH=$(git branch -a | grep "^  remotes/$REPO/" | sed -e "s|.*remotes/$REPO/||")
+        if [ "$(estrlist count $REMOTEBRANCH)" -gt 1 ] ; then
+            fatal "Can't detect remote branch in $REMOTEBRANCH. Run with one from these."
+        fi
         docmd git pull $REBASE $REPO $REMOTEBRANCH
 }