Added .deleteemptyservers command

src/NadekoBot/data/strings/commands/commands.en-US.yml

@@ -2140,4 +2140,8 @@ showembed:
   desc: "Prints the json equivalent of the embed of the message specified by its Id."
   args:
     - "820022733172121600"
-    - "#some-channel 820022733172121600"
+    - "#some-channel 820022733172121600"
+deleteemptyservers:
+  desc: "Deletes all servers in which the bot is the only member."
+  args:
+    - ""

src/NadekoBot/data/strings/responses/responses.en-US.json

@@ -966,5 +966,6 @@
   "favorites": "Favorites",
   "tags": "Tags",
   "imageonly_enable": "This channel is now image-only.",
-  "imageonly_disable": "This channel is no longer image-only."
+  "imageonly_disable": "This channel is no longer image-only.",
+  "deleted_x_servers": "Deleted {0} servers."
 }