Don't try to create temporary database directory if it already exists as doing...

Don't try to create temporary database directory if it already exists as doing so triggers exception before the handle is set which causes update check to fail.

src/alpm_config.vala

@@ -140,10 +140,12 @@ public class AlpmConfig {
 		if (tmp_db) {
 			string tmp_dbpath = "/tmp/pamac-checkdbs";
 			try {
-				Process.spawn_command_line_sync ("mkdir -p %s/sync".printf (tmp_dbpath));
-				Process.spawn_command_line_sync ("ln -sf %slocal %s".printf (dbpath, tmp_dbpath));
-				Process.spawn_command_line_sync ("chmod -R 777 %s/sync".printf (tmp_dbpath));
-				Process.spawn_command_line_sync ("bash -c 'cp -p %ssync/*.{db,files} %s/sync'".printf (dbpath, tmp_dbpath));
+				if (! GLib.FileUtils.test(tmp_dbpath, GLib.FileTest.IS_DIR)) {
+					Process.spawn_command_line_sync ("mkdir -p %s/sync".printf (tmp_dbpath));
+					Process.spawn_command_line_sync ("ln -sf %slocal %s".printf (dbpath, tmp_dbpath));
+					Process.spawn_command_line_sync ("chmod -R 777 %s/sync".printf (tmp_dbpath));
+					Process.spawn_command_line_sync ("bash -c 'cp -p %ssync/*.{db,files} %s/sync'".printf (dbpath, tmp_dbpath));
+				}
 				handle = new Alpm.Handle (rootdir, tmp_dbpath, out error);
 			} catch (SpawnError e) {
 				stderr.printf ("SpawnError: %s\n", e.message);