Unify socket closers. Don't put them all in one try-catch or some might remain.

lib/units/processor/index.js

@@ -161,10 +161,13 @@ module.exports = function(options) {
     .handler())
 
   lifecycle.observe(function() {
-    try {
-      appDealer.close()
-      devDealer.close()
-    }
-    catch (err) {}
+    [appDealer, devDealer].forEach(function(sock) {
+      try {
+        sock.close()
+      }
+      catch (err) {
+        // No-op
+      }
+    })
   })
 }