configure: Fix libs order in check_ld()

With patch and commentary from Lawrence Rust:

'The configure script defines the function check_ld which tests if a
named function can be compiled with specified headers and libraries.
However, the libraries are placed after $extralibs in the linker
invocation which can cause the link to fail if the tested libraries
depend on $extralibs.'

mythtv/configure

@@ -760,7 +760,7 @@ check_ld(){
         test "${f}" = "${f#-l}" && flags="$flags $f" || libs="$libs $f"
     done
     check_cc $($filter_cflags $flags) || return
-    check_cmd $ld $LDFLAGS $flags -o $TMPE $TMPO $extralibs $libs
+    check_cmd $ld $LDFLAGS $flags -o $TMPE $TMPO $libs $extralibs
 }
 
 check_cppflags(){