Don't ask to enable analytics when Do Not Track is enabled

Signed-off-by: Aaron Raimist <aaron@raim.ist>

src/components/structures/LoggedInView.js

@@ -585,7 +585,8 @@ const LoggedInView = createReactClass({
                 limitType={usageLimitEvent.getContent().limit_type}
             />;
         } else if (this.props.showCookieBar &&
-            this.props.config.piwik
+            this.props.config.piwik &&
+            navigator.doNotTrack != 1
         ) {
             const policyUrl = this.props.config.piwik.policyUrl || null;
             topBar = <CookieBar policyUrl={policyUrl} />;