Fix boolean defaults. (#1343) (#1358)

(cherry picked from commit a96f90ff94)

Co-authored-by: Felix Fontein <felix@fontein.de>

plugins/modules/net_tools/haproxy.py

@@ -35,6 +35,7 @@ options:
       - Continue only after the status changes to 'MAINT'.
       - This overrides the shutdown_sessions option.
     type: bool
+    default: false
   host:
     description:
       - Name of the backend host to change.