Set item to default_pointer on dispose, to prevent a panic.

git-svn-id: https://svn.origo.ethz.ch/eiffelstudio/trunk/Src/library/cURL@71170 8089f293-4706-0410-a29e-feb5c42a2edf

curl_form.e

@@ -58,6 +58,7 @@ feature -- Command
 			if item /= default_pointer then
 				create l_curl
 				l_curl.formfree (item)
+				item := default_pointer
 			end
 		end