add previous schema for compat

app/migrations.py

@@ -6,13 +6,16 @@ MIGRATIONS = {
 }
 
 def run_migrations():
-    print("Running migrations...")
-    ran = 0
     db.execute("""
         CREATE TABLE IF NOT EXISTS _migrations(
             id INTEGER PRIMARY KEY
         )
     """)
+    if len(MIGRATIONS) == 0:
+        print("No migrations defined.")
+        return
+    print("Running migrations...")
+    ran = 0
     completed = [row["id"] for row in db.query("SELECT id FROM _migrations")]
     for migration_id in sorted(MIGRATIONS.keys()):
         if migration_id not in completed: