opam: upgrade to 2.0.4

ocaml/opam/Portfile

@@ -3,7 +3,7 @@
 PortSystem          1.0
 PortGroup           github 1.0
 
-github.setup        ocaml opam 2.0.2
+github.setup        ocaml opam 2.0.4
 
 name                opam
 platforms           darwin
@@ -19,9 +19,9 @@ long_description    OPAM is a package manager for OCaml that can install \
 github.tarball_from releases
 distname            opam-full-${version}
 
-checksums           rmd160  dac24c1b89772b39752420b686e3f44d5c6dc44e \
-                    sha256  eeb99fdda4b10ad3467a700fa4d1dfedb30714837d18d2faf1ef9c87d94cf0bc \
-                    size    7869705
+checksums           rmd160  34597d60edb6b00ce2c6b07784003a642ea6e857 \
+                    sha256  debfb828b400fb511ca290f1bfc928db91cad74ec1ccbddcfdbfeff26f7099e5 \
+                    size    7868547
 
 depends_build       port:ocaml
 
@@ -35,12 +35,8 @@ configure.env-append  FETCH=no
 # * patch-makefile.diff is a kludge to put documentation files into
 #   share/doc/opam-installer -- without this, they'd end up in
 #   doc/opam-installer, and there is no /opt/local/doc.
-# * patch-fix-opamarg.diff fixes a temporary problem with the
-#    2.0.2 distribution and should be removed once a later version is
-#    available.
 patchfiles          patch-stop-fetch-check.diff \
-                    patch-makefile.diff \
-                    patch-fix-opamarg.diff
+                    patch-makefile.diff
 
 use_parallel_build  no
 build.target        lib-ext all