Fix sqlite+windows connection issue.

Allows passing object with connection details on windows without a host.
Closes #461

lib/Drivers/DML/sqlite.js

@@ -25,7 +25,7 @@ function Driver(config, connection, opts) {
 		// on Windows, paths have a drive letter which is parsed by
 		// url.parse() as the hostname. If host is defined, assume
 		// it's the drive letter and add ":"
-		if (process.platform == "win32" && config.host.match(/^[a-z]$/i)) {
+		if (process.platform == "win32" && config.host && config.host.match(/^[a-z]$/i)) {
 			this.db = new sqlite3.Database(((config.host ? config.host + ":" : "") + (config.pathname || "")) || ':memory:');
 		} else {
 			this.db = new sqlite3.Database(((config.host ? config.host : "") + (config.pathname || "")) || ':memory:');