do it not only if muxer was not precised

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

remove conditional from configure.ac

modules/misc/gnutls.c:789: undefined reference to `gnutls_certificate_set_x509_crl_file'

It is not clear that static linking is superior in our case
Shared linking could even reduce package size (only one copy of libstdc++ shipped)

21:04 < jon_y> libtool prevents static linking if you are working with dlls, it is by
               design

This works around a conflict with <winioctl.h>.

It does not work on Windows, and is not thread-safe on Linux.