update pbjs callback type to the right one

vuryleo · web-flow · commit b6105c0d2ea4 · 2018-05-02T13:32:55.000+08:00
https://github.com/dcodeIO/protobuf.js/blob/master/cli/pbjs.js#L20
diff --git a/cli/pbjs.d.ts b/cli/pbjs.d.ts
@@ -1,4 +1,4 @@
-type pbjsCallback = (err: Error|null, output?: string) => void;
+type pbjsCallback = (err: Error|null, output?: string) => number|undefined;
 
 /**
  * Runs pbjs programmatically.

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-type pbjsCallback = (err: Error\|null, output?: string) => void;`
	`1`	`+type pbjsCallback = (err: Error\|null, output?: string) => number\|undefined;`
`2`	`2`
`3`	`3`	`/**`
`4`	`4`	`* Runs pbjs programmatically.`