src/trayitemmanager.cpp:253: bad array size

[dcb314]

src/trayitemmanager.cpp:253:38: warning: division 'sizeof (char*) / sizeof (char)' does not compute the number of array elements [-Wsizeof-pointer-div]

Source code is

 if (((sizeof(optarg) / sizeof(*optarg)) > 2) && ((optarg[1] == 'x') || (optarg[1] == 'X'))) {