Handle SIGTERM in fast discovery server (#3381)

Signed-off-by: Mario Dominguez <mariodominguez@eprosima.com>
(cherry picked from commit 60fb557)

Co-authored-by: Mario Domínguez López <116071334+Mario-DL@users.noreply.github.com>

tools/fds/server.cpp

@@ -224,6 +224,7 @@ int main (
 
         // handle signal SIGINT for every thread
         signal(SIGINT, sigint_handler);
+        signal(SIGTERM, sigint_handler);
 
         // Print running server attributes
         cout << "### Server is running ###" << endl;