Try disabling gzip compression of uploads, in case it fixes sync error

Just to see if it fixes the "Error connecting to server" errors some people are
seeing after upgrading to Firefox 46.

chrome/content/zotero/xpcom/sync.js

@@ -1803,7 +1803,8 @@ Zotero.Sync.Server = new function () {
 						
 						var compress = Zotero.Prefs.get('sync.server.compressData');
 						// Compress upload data
-						if (compress) {
+						// TEMP: Disabled in case it fixes sync error in Firefox 46
+						if (false && compress) {
 							// Callback when compressed data is available
 							var bufferUploader = function (data) {
 								var gzurl = url + '?gzip=1';