GUACAMOLE-102: Clean up unused constants; minor comment corrections.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/java/org/apache/guacamole/auth/postgresql/PostgreSQLEnvironment.java

@@ -87,12 +87,6 @@ public class PostgreSQLEnvironment extends JDBCEnvironment {
      */
     private int DEFAULT_MAX_CONNECTIONS = 0;
 
-    /**
-     * The default value for the connection weight for a connection in
-     * a balancing group.
-     */
-    private int DEFAULT_CONNECTION_WEIGHT = 0;
-
     /**
      * The default value for the default maximum number of connections to be
      * allowed to any one connection group. Note that, as long as the legacy