Fix a daemon build error when cgo isn't available

Avoid duplicate definitions of NewSqliteConn when cgo isn't enabled, so
that we can at least build the daemon.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com> (github: nalind)

pkg/graphdb/conn_sqlite3.go

@@ -1,3 +1,5 @@
+// +build cgo
+
 package graphdb
 
 import "database/sql"