Bug 960922 - Disable test_uninstall_errors.html on debug emulator for frequent timeouts

testing/mochitest/b2g-debug.json

@@ -460,6 +460,7 @@
     "dom/apps/tests/test_app_update.html": "debug-only failure",
     "dom/apps/tests/test_packaged_app_install.html": "debug-only failure",
     "dom/apps/tests/test_packaged_app_update.html": "debug-only timeout",
+    "dom/apps/tests/test_uninstall_errors.html": "debug-only timeout",
     "dom/bindings/test/test_exceptions_from_jsimplemented.html": "debug-only failure; bug 926547",
     "dom/camera/test/test_camera.html": "debug-only failure; no assertions when 34 were expected",
     "dom/contacts/tests/test_contacts_basics.html": "debug-only failure",