Compare database server ports using 'eq' instead of with '=='. Avoids

warnings when the port is an empty string.

modules/Bio/EnsEMBL/Storable.pm

@@ -182,9 +182,10 @@ sub is_stored {
   #
   # Databases are the same if they share the same port, host and username
   #
-  if($db->port   == $cur_db->port &&
-     $db->host   eq $cur_db->host &&
-     $db->dbname eq $cur_db->dbname) {
+  if ( $db->port() eq $cur_db->port()
+    && $db->host()   eq $cur_db->host()
+    && $db->dbname() eq $cur_db->dbname() )
+  {
     return 1;
   }