Update null check for `modifiedAssets` array.

Co-Authored-By: emizzle <ericmastro@status.im>

lib/modules/pipeline/index.js

@@ -86,7 +86,7 @@ class Pipeline {
       function shouldRunWebpack(next){
         // assuming we got here because an asset was changed, let's check our webpack config
         // to see if the changed asset requires webpack to run
-        if(modifiedAssets){
+        if(modifiedAssets || modifiedAssets.length) {
           const configReader = new WebpackConfigReader({webpackConfigName: self.webpackConfigName});
           return configReader.readConfig((err, config) => {
             if(err) return next(err);