Remove pidfile when shutting down, fixes #1470

Changes.md

@@ -3,6 +3,7 @@ HEAD
 
 - A `USR2` signal will now reopen _all_ logs, using IO#reopen. Thus, instead of creating a new Logger object, 
   Sidekiq will now just update the existing Logger's file descriptor [#1163].
+- Remove pidfile when shutting down if started with `-P` [#1470]
 
 2.17.4
 -----------

lib/sidekiq/cli.rb

@@ -314,6 +314,9 @@ module Sidekiq
           f.puts Process.pid
         end
       end
+      at_exit do
+        FileUtils.rm_f path
+      end
     end
 
     def parse_config(cfile)

lib/sidekiq/version.rb

@@ -1,3 +1,3 @@
 module Sidekiq
-  VERSION = "2.17.4"
+  VERSION = "2.17.5"
 end