back out ffdc872d5450 (https://bugzilla.mozilla.org/show_bug.cgi?id=699942#c4)

browser/locales/en-US/chrome/browser/browser.properties

@@ -331,7 +331,7 @@ syncPromoNotification.learnMoreLinkText=Learn More
 # and %2$S by the value of the toolkit.telemetry.server_owner preference.
 telemetryPrompt = Will you help improve %1$S by sending anonymous information about performance, hardware characteristics, feature usage, and browser customizations to %2$S?
 telemetryLinkLabel = Learn More
-telemetryYesButtonLabel = Yes, I want to help
+telemetryYesButtonLabel = Yes
 telemetryYesButtonAccessKey = Y
 telemetryNoButtonLabel = No
 telemetryNoButtonAccessKey = N