all: move description of C files below the copyright and license

src/plugins/irc/irc-server.c

@@ -1,6 +1,4 @@
 /*
- * irc-server.c - I/O communication with IRC servers
- *
  * SPDX-FileCopyrightText: 2003-2025 Sébastien Helleu <flashcode@flashtux.org>
  * SPDX-FileCopyrightText: 2005-2010 Emmanuel Bouthenot <kolter@openics.org>
  * SPDX-FileCopyrightText: 2012 Simon Arlott
@@ -23,6 +21,8 @@
  * along with WeeChat.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+/* I/O communication with IRC servers */
+
 #include <stdlib.h>
 #include <stddef.h>
 #include <unistd.h>