get raw hex from the new github url

manifest.json

@@ -21,6 +21,7 @@
     "permissions": [
         "https://www.google-analytics.com/",
         "https://*.github.com/",
+        "https://*.githubusercontent.com/",
         "serial",
         "storage",
         "fileSystem",

tabs/firmware_flasher.js

@@ -61,7 +61,7 @@ function tab_initialize_firmware_flasher() {
         });
 
         $('a.load_remote_file').click(function() {
-            $.get('https://raw.github.com/multiwii/baseflight/master/obj/baseflight.hex', function(data) {
+            $.get('https://raw.githubusercontent.com/multiwii/baseflight/master/obj/baseflight.hex', function(data) {
                 intel_hex = data;
 
                 parse_hex(intel_hex, function(data) {