Fix indentation in run script and update submodule

Tools/sitl_gazebo

@@ -1 +1 @@
-Subproject commit dc60f209db24712721dd9481e2244b7b0b35a9db
+Subproject commit e56ecf388d1c16599772ef5a9044af5d18bb05d0

test/mavsdk_tests/waitforgz.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
 
-while gz stats -d 0 2>&1 | grep "An instance of Gazebo is not running."; do
+while gz stats -d 0 2>&1 | grep -q "An instance of Gazebo is not running."; do
     echo "Gazebo not running yet ..."
 done