component/ghostscript: remove ignored --disable-threadsafe

INFO configure: WARNING: unrecognized options: --disable-threadsafe

component/ghostscript/buildout.cfg

@@ -21,7 +21,6 @@ pkg_config_depends = ${libidn:location}/lib/pkgconfig:${libtiff:location}/lib/pk
 # XXX --with-tessdata work arounds a slaprunner bug of having softwares installed in a path containing //
 configure-options =
   --disable-cups
-  --disable-threadsafe
   --with-system-libtiff
   --without-so
   --without-x