Fix for #143: Let the driver determine the dataset location if non given (#301)

* Removed the else statement from the open function. Based on the Google Simba driver documentation, the location is automatically handled based on where the dataset exists.

* Removed the location variable that wasn't used and refactored the if condition for the open function.

Author: Tylorjg

src/main/java/liquibase/ext/bigquery/database/BigqueryConnection.java

@@ -20,7 +20,6 @@
  */
 
 public class BigqueryConnection extends JdbcConnection {
-    private String location = "US";
     private S42Connection con;
 
     public BigqueryConnection() {
@@ -87,10 +86,8 @@ public Connection getUnderlyingConnection() {
     @Override
     public void open(String url, Driver driverObject, Properties driverProperties) throws DatabaseException {
         if (driverProperties.stringPropertyNames().contains("Location")) {
-            this.location = driverProperties.getProperty("Location");
-        } else {
-            this.location = getUrlParamValue(url, "Location", "US");
-            driverProperties.setProperty("Location", this.location);
+            String locationValue = getUrlParamValue(url, "Location");
+            driverProperties.setProperty("Location", locationValue);
         }
 
         Scope.getCurrentScope().getLog(this.getClass()).fine(String.format("Opening connection to %s  driverProperties=%s", url, driverProperties));