Make StubSocket#close work as one might expect

Author: rzane

lib/webmock/http_lib_adapters/net_http.rb

@@ -128,7 +128,11 @@ def start_without_connect
 
 
         def ensure_actual_connection
-          do_start if @socket.is_a?(StubSocket)
+          if @socket.is_a?(StubSocket)
+            @socket&.close
+            @socket = nil
+            do_start
+          end
         end
 
         alias_method :start_with_connect, :start
@@ -232,13 +236,16 @@ class StubSocket #:nodoc:
   attr_accessor :read_timeout, :continue_timeout, :write_timeout
 
   def initialize(*args)
+    @closed = false
   end
 
   def closed?
-    @closed ||= true
+    @closed
   end
 
   def close
+    @closed = true
+    nil
   end
 
   def readuntil(*args)