remove code that pushes arrays of dependencies into dependencies

the actua dep population is done in lines 155-159

lib/optimize/ConcatenatedModule.js

@@ -143,7 +143,7 @@ class ConcatenatedModule extends Module {
 		this.cacheable = modules.every(m => m.cacheable);
 		const modulesSet = new Set(modules);
 		this.reasons = rootModule.reasons.filter(reason => !modulesSet.has(reason.module));
-		this.dependencies = [].concat.apply([], modules.map(m => m.dependencies.filter(dep => !modulesSet.has(dep.module))));
+		this.dependencies = [];
 		this.meta = rootModule.meta;
 		this.dependenciesWarnings = modules.reduce((w, m) => m.dependenciesWarnings.forEach(x => w.push(x)), []);
 		this.dependenciesErrors = modules.reduce((w, m) => m.dependenciesErrors.forEach(x => w.push(x)), []);