Delete the useless pin-depends on dkim

Author: dinosaure

packages/dkim/dkim.0.7.0/opam

@@ -19,7 +19,7 @@ build: [
 depends: [
   "ocaml"             {>= "4.08.0"}
   "dune"              {>= "2.0.0"}
-  "mrmime"            {>= "0.5.0"}
+  "mrmime"            {>= "0.6.1"}
   "digestif"          {>= "0.9.0"}
   "ipaddr"
   "astring"           {>= "0.8.5"}
@@ -39,9 +39,6 @@ depends: [
   "alcotest"          {with-test}
 ]
 
-pin-depends: [
-  [ "mrmime.0.7.0" "git+https://github.com/hannesm/mrmime.git#60dc0cd3befab0af6c0418d97c3927fe9ec5650b" ]
-]
 url {
   src:
     "https://github.com/mirage/ocaml-dkim/releases/download/v0.7.0/dkim-0.7.0.tbz"