Revert "Update firefox binary launcher dependencies to 2.46.0"

This reverts commit e251f6ddbb11cf7e1b88a6e9654b49a6474feb0c.
We're running into issues getting the webdriver.xpi exported from the
2.46.0 jar to work with IO::Uncompress::Unzip.

The previous webdriver.xpi seems to work fine with Firefox 38.0.5 so
perhaps we'll hold off for now.

see also: #201

Changes

@@ -1,9 +1,6 @@
 Revision history for Selenium-Remote-Driver
 
-0.2651 06-17-2015
-        (selenium version: 2.46.0)
-
-0.26   05-16-2015
+0.26   05-16-215
         (selenium version: 2.45.0)
 
         [NEW FEATURES]

lib/Selenium/Firefox/webdriver_prefs.json

@@ -2,7 +2,6 @@
   "frozen": {
     "app.update.auto": false,
     "app.update.enabled": false,
-    "browser.displayedE10SNotice": 4,
     "browser.download.manager.showWhenStarting": false,
     "browser.EULA.override": true,
     "browser.EULA.3.accepted": true,
@@ -12,7 +11,6 @@
     "browser.safebrowsing.enabled": false,
     "browser.safebrowsing.malware.enabled": false,
     "browser.search.update": false,
-    "browser.selfsupport.url" : "",
     "browser.sessionstore.resume_from_crash": false,
     "browser.shell.checkDefaultBrowser": false,
     "browser.tabs.warnOnClose": false,