Correct spelling of fission, a=testonly

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1586225
gecko-commit: 3cb6ff0bdc9d33ff1ba8c9606d69f3f6a104b163
gecko-integration-branch: mozilla-inbound
gecko-reviewers: testonly

Author: jgraham

tools/wptrunner/wptrunner/browsers/firefox.py

@@ -198,7 +198,7 @@ def run_info_browser_version(binary):
 
 
 def update_properties():
-    return (["os", "debug", "webrender", "fisson", "e10s", "sw-e10s", "processor"],
+    return (["os", "debug", "webrender", "fission", "e10s", "sw-e10s", "processor"],
             {"os": ["version"], "processor": ["bits"]})