Update user.js

Added preference to remove rounded corners for web content.

Author: Godiesc

user.js

@@ -7,6 +7,7 @@ user_pref("svg.context-properties.content.enabled", true);
 user_pref("browser.tabs.delayHidingAudioPlayingIconMS", 0);
 user_pref("browser.newtabpage.activity-stream.improvesearch.handoffToAwesomebar", false);
 user_pref("browser.tabs.allow_transparent_browser", true);
+user_pref("sidebar.revamp.round-content-area", false);
 
 /*To active container tabs without any extension */
 user_pref("privacy.userContext.enabled", true);