Fix Requires for postgresql

Change-Id: I2382367ac8ab1a03d99f02b7beb4c9ee0cad34d4
diff --git a/vland.service b/vland.service
index 2203136..fab2639 100644
--- a/vland.service
+++ b/vland.service
@@ -2,7 +2,7 @@
 
 [Unit]
 Description=VLAN daemon
-Requires=postgresql
+Requires=postgresql.service
 
 [Service]
 Type=simple