Get rid of IOError2

Author: pulsejet

binding-mruby/binding-util.cpp

@@ -71,8 +71,7 @@ static const MrbExcData excData[] =
 	{ Shutdown, "SystemExit"  },
 	{ PHYSFS,   "PHYSFSError" },
 	{ SDL,      "SDLError"    },
-	{ MKXP,     "MKXPError"   },
-	{ IO,       "IOError2"     }
+	{ MKXP,     "MKXPError"   }
 };
 
 static elementsN(excData);