bind: Attempt to fix Darwin OpenSSL linking

Issue NixOS#15279 reports:

````
Checking for OpenSSL library... using OpenSSL from /nix/store/c6kijfc5py2805lmqczvmcws5cm9jg1l-openssl-1.0.2g-dev/lib and /nix/store/c6kijfc5py2805lmqczvmcws5cm9jg1l-openssl-1.0.2g-dev/include
checking whether linking with OpenSSL works... no
configure: error: Could not run test program using OpenSSL from
/nix/store/c6kijfc5py2805lmqczvmcws5cm9jg1l-openssl-1.0.2g-dev/lib and /nix/store/c6kijfc5py2805lmqczvmcws5cm9jg1l-openssl-1.0.2g-dev/include.
Please check the argument to --with-openssl and your
shared library configuration (e.g., LD_LIBRARY_PATH).
builder for ‘/nix/store/54nni99j4ycwws6zfjwcvv8vxsdk895i-bind-9.10.4.drv’ failed with exit code 1
````

pkgs/servers/dns/bind/darwin-openssl-linking-fix.patch

@@ -0,0 +1,26 @@
+diff --git a/configure b/configure
+index 6779cc3..4275520 100755
+--- a/configure
++++ b/configure
+@@ -15707,21 +15707,6 @@ $as_echo "not found" >&6; }
+ 			*-hp-hpux*)
+ 				DST_OPENSSL_LIBS="-L$use_openssl/lib -Wl,+b: -lcrypto"
+ 				;;
+-			*-apple-darwin*)
+-				#
+-				# Apple's ld seaches for serially for dynamic
+-				# then static libraries.  This means you can't
+-				# use -L to override dynamic system libraries
+-				# with static ones when linking.  Instead
+-				# we specify a absolute path.
+-				#
+-				if test -f "$use_openssl/lib/libcrypto.dylib"
+-				then
+-					DST_OPENSSL_LIBS="-L$use_openssl/lib -lcrypto"
+-				else
+-					DST_OPENSSL_LIBS="$use_openssl/lib/libcrypto.a"
+-				fi
+-				;;
+ 			*)
+ 				DST_OPENSSL_LIBS="-L$use_openssl/lib -lcrypto"
+ 				;;

pkgs/servers/dns/bind/default.nix

@@ -10,7 +10,8 @@ stdenv.mkDerivation rec {
     sha256 = "0mmhzi4483mkak47wj255a36g3v0yilxwfwlbckr1hssinri5m7q";
   };
 
-  patches = [ ./remove-mkdir-var.patch ];
+  patches = [ ./remove-mkdir-var.patch ] ++
+    stdenv.lib.optional stdenv.isDarwin ./darwin-openssl-linking-fix.patch;
 
   buildInputs = [ openssl libtool perl libxml2 ];