Fix build.js

A single JS file can be bundled in multiple
output JS files, so removed `break` in the loop.

frappe/build.js

@@ -272,7 +272,6 @@ function watch_js(ondirty) {
 			if (sources.includes(filename)) {
 				pack(target, sources);
 				ondirty && ondirty(target);
-				break;
 			}
 		}
 	});