configure: do not require iconv

On Windows, we use the Win32 for Unicode conversion. On OSX, we don't
even need to convert (and probably not on recent Linux distros either,
but they all have iconv anyway :) )

configure.ac

@@ -431,8 +431,6 @@ dnl
 dnl Iconv stuff
 dnl
 AM_ICONV
-AS_IF([test "$am_cv_func_iconv" != "yes"],
-	[AC_MSG_ERROR([libiconv is needed for VLC to work properly])])
 VLC_ADD_CFLAGS([libvlc],[${INCICONV}])
 VLC_ADD_LIBS([libvlc],[${LTLIBICONV}])