accelgroup: Fix a doc comment

The escaping madness with gtk-doc is different.

Lets see if this works.

gtk/gtkaccelgroup.c

@@ -1440,14 +1440,14 @@ out:
  *     modifier mask, %NULL
  *
  * Parses a string representing an accelerator. The format looks like
- * “<Control>a” or “<Shift><Alt>F1” or “<Release>z” (the last one is
+ * `<Control>a` or `<Shift><Alt>F1` or `<Release>z` (the last one is
  * for key release).
  *
  * The parser is fairly liberal and allows lower or upper case, and also
- * abbreviations such as “<Ctl>” and “<Ctrl>”. Key names are parsed using
+ * abbreviations such as `<Ctl>` and `<Ctrl>`. Key names are parsed using
  * gdk_keyval_from_name(). For character keys the name is not the symbol,
- * but the lowercase name, e.g. one would use “<Ctrl>minus” instead of
- * “<Ctrl>-”.
+ * but the lowercase name, e.g. one would use `<Ctrl>minus` instead of
+ * `<Ctrl>-`.
  *
  * If the parse fails, @accelerator_key and @accelerator_mods will
  * be set to 0 (zero).