fix BinDeps.shlib_ext dep warn in build script

Author: visr

deps/build.jl

@@ -8,7 +8,7 @@ end)
 version = "3.6.1"
 
 provides(Sources, URI("http://download.osgeo.org/geos/geos-$(version).tar.bz2"), [libgeos], os = :Unix)
-provides(BuildProcess,Autotools(libtarget = "capi/.libs/libgeos_c."*BinDeps.shlib_ext),libgeos)
+provides(BuildProcess,Autotools(libtarget = "capi/.libs/libgeos_c."*Libdl.dlext),libgeos)
 # provides(AptGet,"libgeos-dev", libgeos)
 # TODO: provides(Yum,"libgeos-dev", libgeos)
 # TODO: provides(Pacman,"libgeos-dev", libgeos)