Fix typo in the default configuration of the trigger hotkeys.

According to setup/keyboardshortcut.py, "Control" seems to be correct.

BUG=none
TEST=compile ibus with --enable-memconf, start ibus-daemon, start ibus-setup, click "..." button for the "Enable or disable" hotkey, then verify that the "Control" checkbox in the pop-up dialog is checked from the beginning.

Review URL: http://codereview.appspot.com/4017042

ibus/common.py

@@ -146,7 +146,7 @@ DEFAULT_ASYNC_HANDLERS = {
 
 CONFIG_GENERAL_SHORTCUT_TRIGGER     = "/general/keyboard_shortcut_trigger"
 CONFIG_GENERAL_SHORTCUT_TRIGGER_DEFAULT = [
-    "Ctrl+space",
+    "Control+space",
     "Zenkaku_Hankaku",
     "Hangul"]
 CONFIG_GENERAL_SHORTCUT_NEXT_ENGINE = "/general/keyboard_shortcut_next_engine"