Fix opencv detection.

This commit changes the ".so" argument placement in check_ld sub-program.

configure

@@ -789,8 +789,8 @@ check_ld(){
     log check_ld "$@"
     type=$1
     shift 1
-    flags=$(filter_out '-l*' $@)
-    libs=$(filter '-l*' $@)
+    flags=$(filter_out '-l*|*.so' $@)
+    libs=$(filter '-l*|*.so' $@)
     check_$type $($cflags_filter $flags) || return
     flags=$($ldflags_filter $flags)
     libs=$($ldflags_filter $libs)