gitlab/gitlab-unicorn-startup: Factor our psql call

We'll need to invoke psql connected to gitlab db in another place, so
before doing it let's factor out the code to call psql as connected to a
separate function.

software/gitlab/gitlab-unicorn-startup.in

@@ -9,6 +9,15 @@ die() {
     exit 1
 }
 
+# run psql on gitlab db
+psql() {
+    {{ psql_bin }}  \
+        -h {{ pgsql['pgdata-directory'] }}  \
+        -U {{ pgsql.superuser }}            \
+        -d {{ pgsql.dbname }}               \
+        "$@"
+}
+
 # 1. what to do when instance is initially setup
 # see
 #   https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/files/gitlab-cookbooks/gitlab/recipes/database_migrations.rb
@@ -18,12 +27,7 @@ die() {
 # ( first quering PG several times waiting a bit till postgresql is started and ready )
 tpgwait=5
 while true; do
-    pgtables="$({{ psql_bin }}   \
-        -h {{ pgsql['pgdata-directory'] }}  \
-        -U {{ pgsql.superuser }}            \
-        -d {{ pgsql.dbname }}               \
-        -c '\d')" && break
-
+    pgtables="$(psql -c '\d')" && break
     tpgwait=$(( $tpgwait - 1 ))
     test $tpgwait = 0 && die "pg query problem"
     echo "I: PostgreSQL is not ready (yet ?); will retry $tpgwait times..." 1>&2

software/gitlab/software.cfg

@@ -243,7 +243,7 @@ md5sum  = cdcb2036c33da547a2cf5d0515cf48ff
 
 [gitlab-unicorn-startup.in]
 <= download-file
-md5sum  = 14c5632182d830c03f7788c85d6f4da1
+md5sum  = e68d1b5376e79c5e606dce050c633d27
 
 [gitlab.yml.in]
 <= download-template