Append warning if Impersonation is enable without prefix (#1664)

lemonldap-ng-manager/lib/Lemonldap/NG/Manager/Conf/Tests.pm

@@ -642,6 +642,16 @@ sub tests {
             # Return
             return 1;
         },
+
+        # Warn if Impersonation is enabled without prefix
+        impersonationPrefix => sub {
+            return 1 unless ( $conf->{impersonationRule} );
+            return ( 1, "Impersonation is enabled without real attributes prefix" )
+              unless ( $conf->{impersonationPrefix} );
+
+            # Return
+            return 1;
+        },
     };
 }