Bug 1854463 - run_operations.py - only print stderr if capture_output is true for run_shell command. r=dbaker DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D188878

dom/media/webrtc/third_party_build/run_operations.py

@@ -68,7 +68,8 @@ def run_shell(cmd, capture_output=True):
             "Hit return code {} running '{}'. Aborting.".format(res.returncode, cmd),
             file=sys.stderr,
         )
-        print(res.stderr)
+        if capture_output:
+            print(res.stderr)
         sys.exit(1)
     output_lines = []
     if capture_output: