gnu: Add rust-postgres-protocol-0.6.

* gnu/packages/crates-io.scm (rust-postgres-protocol-0.6): New variable.
(rust-postgres-protocol-0.3): Inherit from rust-postgres-protocol-0.6.

Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/packages/crates-io.scm

@@ -32865,8 +32865,41 @@ UDP.")
      "This is an internal crate used by postgres-types.")
     (license (list license:expat license:asl2.0))))
 
+(define-public rust-postgres-protocol-0.6
+  (package
+    (name "rust-postgres-protocol")
+    (version "0.6.1")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (crate-uri "postgres-protocol" version))
+        (file-name
+         (string-append name "-" version ".tar.gz"))
+        (sha256
+         (base32
+          "1wxzs78zvz00bh3bhbbp9hnq9hg77f8h5pzjmcy9481fsdq0ygpz"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:cargo-inputs
+       (("rust-base64" ,rust-base64-0.13)
+        ("rust-byteorder" ,rust-byteorder-1)
+        ("rust-bytes" ,rust-bytes-1)
+        ("rust-fallible-iterator" ,rust-fallible-iterator-0.2)
+        ("rust-hmac" ,rust-hmac-0.10)
+        ("rust-md-5" ,rust-md-5-0.9)
+        ("rust-memchr" ,rust-memchr-2)
+        ("rust-rand" ,rust-rand-0.8)
+        ("rust-sha2" ,rust-sha2-0.9)
+        ("rust-stringprep" ,rust-stringprep-0.1))))
+    (home-page "https://github.com/sfackler/rust-postgres")
+    (synopsis "Low level Postgres protocol APIs")
+    (description
+     "This package provides low level Postgres protocol APIs.")
+    (license (list license:expat license:asl2.0))))
+
 (define-public rust-postgres-protocol-0.3
   (package
+    (inherit rust-postgres-protocol-0.6)
     (name "rust-postgres-protocol")
     (version "0.3.2")
     (source
@@ -32876,7 +32909,6 @@ UDP.")
        (file-name (string-append name "-" version ".tar.gz"))
        (sha256
         (base32 "04kkznbhwspfn0hdja3jsv37l6g5gz7a625z8yra325zamjfd1r4"))))
-    (build-system cargo-build-system)
     (arguments
      `(#:skip-build? #t
        #:cargo-inputs
@@ -32890,12 +32922,7 @@ UDP.")
         ("rust-memchr" ,rust-memchr-1)
         ("rust-rand" ,rust-rand-0.3)
         ("rust-sha2" ,rust-sha2-0.7)
-        ("rust-stringprep" ,rust-stringprep-0.1))))
+        ("rust-stringprep" ,rust-stringprep-0.1))))))
-    (home-page "https://github.com/sfackler/rust-postgres")
-    (synopsis "Low level Postgres protocol APIs")
-    (description
-     "This package provides low level Postgres protocol APIs.")
-    (license (list license:expat license:asl2.0))))
 
 (define-public rust-postgres-shared-0.4
   (package