Revert "gnu: nss, nss-certs: Update to 3.30.1."

This version fails to build on some architectures:

https://lists.gnu.org/archive/html/guix-devel/2017-04/msg00365.html
https://bugzilla.mozilla.org/show_bug.cgi?id=1351459

This reverts commit 96e98d51a7.

gnu/packages/certs.scm

@@ -74,7 +74,7 @@
 (define-public nss-certs
   (package
     (name "nss-certs")
-    (version "3.30.1")
+    (version "3.30")
     (source (origin
               (method url-fetch)
               (uri (let ((version-with-underscores
@@ -85,7 +85,7 @@
                       "nss-" version ".tar.gz")))
               (sha256
                (base32
-                "1djypq081m22iw0wg0q7gnpndam5f8qjhqfd5v9by4c6l6lp78hz"))))
+                "1agkkwb51si4raw46p44vl3d0l7wzvdjcblpcdjjz6aymq6h1h58"))))
     (build-system gnu-build-system)
     (outputs '("out"))
     (native-inputs

gnu/packages/gnuzilla.scm

@@ -194,7 +194,7 @@ in the Mozilla clients.")
 (define-public nss
   (package
     (name "nss")
-    (version "3.30.1")
+    (version "3.30")
     (source (origin
               (method url-fetch)
               (uri (let ((version-with-underscores
@@ -205,7 +205,7 @@ in the Mozilla clients.")
                       "nss-" version ".tar.gz")))
               (sha256
                (base32
-                "1djypq081m22iw0wg0q7gnpndam5f8qjhqfd5v9by4c6l6lp78hz"))
+                "1agkkwb51si4raw46p44vl3d0l7wzvdjcblpcdjjz6aymq6h1h58"))
               ;; Create nss.pc and nss-config.
               (patches (search-patches "nss-pkgconfig.patch"
                                        "nss-increase-test-timeout.patch"))))