only run extractFramesGecko when required

src/parse-stacktrace.js

@@ -99,7 +99,8 @@ function extractFrames(stack) {
 	// TODO: Maybe make this code even more cautious, and match each stacktrace line individually, aborting as soon as any one line cannot be parsed?
 	return defaultValue(
 		extractFramesV8(stack),
-		extractFramesGecko(stack)
+		() => extractFramesGecko(stack),
+		{ evaluate: true }
 	);
 }