Patch by Robert Scheck <robert@fedoraproject.org> for eggdrop <= 1.6.21, which fixes the build failures if
compiled with "-Werror=format-security".

--- eggdrop1.6.21/src/main.c						2011-09-23 22:31:32.000000000 +0200
+++ eggdrop1.6.21/src/main.c.format-security				2017-07-27 01:51:09.000000000 +0200
@@ -496,7 +496,7 @@
         break;                  /* this should never be reached */
       case 'h':
         printf("\n%s\n\n", version);
-        printf(EGG_USAGE);
+        printf("%s", EGG_USAGE);
         printf("\n");
         bg_send_quit(BG_ABORT);
         exit(0);
@@ -1063,7 +1063,7 @@
   putlog(LOG_ALL, "*", "--- Loading %s (%s)", ver, s);
   chanprog();
   if (!encrypt_pass) {
-    printf(MOD_NOCRYPT);
+    printf("%s", MOD_NOCRYPT);
     bg_send_quit(BG_ABORT);
     exit(1);
   }
--- eggdrop1.6.21/src/misc.c						2011-07-09 17:07:48.000000000 +0200
+++ eggdrop1.6.21/src/misc.c.format-security				2017-07-27 01:53:17.000000000 +0200
@@ -601,7 +601,7 @@
                * then reset repeats. We want the current time here,
                * so put that in the file first.
                */
-              fprintf(logs[i].f, stamp);
+              fprintf(logs[i].f, "%s", stamp);
               fprintf(logs[i].f, MISC_LOGREPEAT, logs[i].repeats);
               logs[i].repeats = 0;
               /* No need to reset logs[i].szlast here
--- eggdrop1.6.21/src/mod/transfer.mod/transfer.c			2011-02-13 15:19:34.000000000 +0100
+++ eggdrop1.6.21/src/mod/transfer.mod/transfer.c.format-security	2017-07-27 01:58:04.000000000 +0200
@@ -786,7 +786,7 @@
 
 static void display_dcc_fork_send(int idx, char *buf)
 {
-  sprintf(buf, TRANSFER_CONN_SEND);
+  sprintf(buf, "%s", TRANSFER_CONN_SEND);
 }
 
 static int expmem_dcc_xfer(void *x)