Fix crash with long function names

This fixes a buffer overrun introduced by commit eba8474294c1c106dd6e4f62a73160798f16458d.

The crash happens in do_call() when a function name was longer than
the max. allowed (sNAMEMAX) because of the leading '.' (dot) inserted
in command().

--------- test code --------

#include <a_samp>

OverlyLongFunctionNameYouCantEvenBotherToRead() {
	print("hey");
}

main() {
	OverlyLongFunctionNameYouCantEvenBotherToRead();
}

----- end of test code -----