Corteza no longer defaults to MySQL db

Default DB_DSN changed from
mysql://corteza:corteza@tcp(db:3306)/corteza?collation=utf8mb4_general_ci

to
sqlite3://file::memory:?cache=shared&mode=memory

pkg/options/db.go

@@ -2,7 +2,6 @@ package options
 
 import (
 	"strings"
-	"time"
 )
 
 type (
@@ -12,16 +11,13 @@ type (
 )
 
 func DB(pfix string) (o *DBOpt) {
-	const delay = 15 * time.Second
-	const maxTries = 100
-
 	o = &DBOpt{
-		DSN: "mysql://corteza:corteza@tcp(db:3306)/corteza?collation=utf8mb4_general_ci",
+		DSN: "sqlite3://file::memory:?cache=shared&mode=memory",
 	}
 
 	fill(o)
 
-	if !strings.Contains(o.DSN, "://") {
+	if o.DSN != "" && !strings.Contains(o.DSN, "://") {
 		// Make sure DSN is compatible with new requirements
 		o.DSN = "mysql://" + o.DSN
 	}