Don't print blank stdout in extension installers

modules/launch_utils.py

@@ -228,7 +228,9 @@ def run_extension_installer(extension_dir):
         env = os.environ.copy()
         env['PYTHONPATH'] = f"{os.path.abspath('.')}{os.pathsep}{env.get('PYTHONPATH', '')}"
 
-        print(run(f'"{python}" "{path_installer}"', errdesc=f"Error running install.py for extension {extension_dir}", custom_env=env))
+        stdout = run(f'"{python}" "{path_installer}"', errdesc=f"Error running install.py for extension {extension_dir}", custom_env=env)
+        if stdout:
+            print(stdout)
     except Exception as e:
         errors.report(str(e))