ports/58513: net/ap-utils: fix libintl and libiconv depedencies => avoid conflicts with other ports

[Simon Barner]

>  Port maintainer's comment:
>  I don't know much about the libintl issue. All I can say is that the patch
>  tests ok for me. Assuming there is a problem, I recommend to commit this
>  patch. Only change is to bump PORTREVISION to 2.

The libintl issue is that some ports (including this one here) build an
internal version of libintl instead of using the system wide library
that is provided by the gettext port.
While those ports run fine, they install a file
${PREFIX}/lib/charset.alias which is overwritten by every port that does
not make use of the system wide libintl.

My patches fix two problems:
 - avoid clashing of multiple charset.alias files.
 - reduce code bloat by using the system wide (dynamic) library instead
   of using a (static) internal one.

Regards,
 Simon