component/firewalld: Expose real process with wrapper

Missing exec results with receiving signals to the wrapper itself, leaving
the child process escaping signal control.

component/firewalld/buildout.cfg

@@ -136,7 +136,7 @@ command =
   cp -f ${firewalld:location}/lib/firewalld/zones/trusted.xml ${firewalld:etc-dir}/zones/
   cp -f ${firewalld:location}/share/dbus-1/system.d/FirewallD.conf ${dbus:location}/share/dbus-1/system.d/
   mkdir -p ${firewalld:location}/sbin
-  echo -n '#!/bin/sh\nLD_LIBRARY_PATH=${nftables:location}/lib ${firewalld:location}/${firewalld:sbin-dir}/firewalld "$@"' > ${firewalld:location}/sbin/firewalld
+  echo -n '#!/bin/sh\nLD_LIBRARY_PATH=${nftables:location}/lib exec ${firewalld:location}/${firewalld:sbin-dir}/firewalld "$@"' > ${firewalld:location}/sbin/firewalld
   chmod a+x ${firewalld:location}/sbin/firewalld
 
 update-command = ${:command}