dereference double pointer before use for go 1.4 compatibility

database/postgis/util.go

@@ -3,6 +3,7 @@ package postgis
 import (
 	"database/sql"
 	"fmt"
+	_ "log"
 	"os"
 	"strings"
 	"sync"
@@ -94,7 +95,7 @@ func dropTableIfExists(tx *sql.Tx, schema, table string) error {
 // rollbackIfTx rollsback transaction if tx is not nil.
 func rollbackIfTx(tx **sql.Tx) {
 	if *tx != nil {
-		if err := tx.Rollback(); err != nil {
+		if err := (*tx).Rollback(); err != nil {
 			log.Fatal("rollback failed", err)
 		}
 	}