[sysadmin-bin] Bash has no booleans support

[Andrea Veri <av src gnome org>]

commit 8625f2cb4d9e227b6522ca60582290e6c522c8b1
Author: Andrea Veri <averi redhat com>
Date:   Fri Dec 15 15:46:06 2017 +0100

    Bash has no booleans support

 git/pre-receive-check-policy |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/git/pre-receive-check-policy b/git/pre-receive-check-policy
index 3f1982f..584b415 100755
--- a/git/pre-receive-check-policy
+++ b/git/pre-receive-check-policy
@@ -162,7 +162,7 @@ check_ref_update() {
                                 nonfastforward=true
                             fi
                         elif [ "`hostname`" == 'gitlab.gnome.org' ]; then
-                            if [[ $is_master || $is_gnome ]]; then
+                            if [[ "$is_master" = true || "$is_gnome" = true ]]; then
                                 nonfastforward=true
                             fi
                         fi