nagios: fix build

The compiler complains about dl* function missing, this commit adds the
necessary flag to pass to gcc to make it build correctly

(cherry picked from commit 213623e291)

maintainers/maintainer-list.nix

@@ -3541,6 +3541,12 @@
     githubId = 993484;
     name = "Greg Hale";
   };
+  immae = {
+    email = "ismael@bouya.org";
+    github = "immae";
+    githubId = 510202;
+    name = "Ismaël Bouya";
+  };
   imuli = {
     email = "i@imu.li";
     github = "imuli";

pkgs/servers/monitoring/nagios/default.nix

@@ -14,6 +14,7 @@ stdenv.mkDerivation rec {
 
   configureFlags = [ "--localstatedir=/var/lib/nagios" ];
   buildFlags = [ "all" ];
+  CFLAGS = "-ldl";
 
   # Do not create /var directories
   preInstall = ''
@@ -36,6 +37,6 @@ stdenv.mkDerivation rec {
     homepage    = "https://www.nagios.org/";
     license     = stdenv.lib.licenses.gpl2;
     platforms   = stdenv.lib.platforms.linux;
-    maintainers = with stdenv.lib.maintainers; [ thoughtpolice relrod ];
+    maintainers = with stdenv.lib.maintainers; [ immae thoughtpolice relrod ];
   };
 }