Ignore schema attribute in PATCH payload.

Fixes #273.

lib/www/server/lib/db/project/configuration/patch.js

@@ -36,6 +36,9 @@ async function patch (projectId, payload, opts = {}) {
 			}
 		}
 
+		// We do not allow users to change the schema
+		delete payload.schema;
+
 		const dest = removeNulls(deepMerge(source, payload));
 		await modify(projectId, dest);
 		return dest;