Allow missing patch files for downgrade or testing pr.

server/database.js

@@ -358,10 +358,16 @@ class Database {
                 directory: Database.knexMigrationsPath,
             });
         } catch (e) {
+            // Allow missing patch files for downgrade or testing pr.
+            if (e.message.includes("the following files are missing:")) {
+                log.warn("db", e.message);
+                log.warn("db", "Database migration failed, you may be downgrading Uptime Kuma.");
+            } else {
                 log.error("db", "Database migration failed");
                 throw e;
             }
         }
+    }
 
     /**
      * TODO