mysql: include dprint.h

- several files were missing include of dprint.h
- could be the cause for missing symbol reported by Pratab Ali for
  opensuse
(cherry picked from commit 9c5da73226b3124c888e434e3df55cc1466b3b07)

modules/db_mysql/km_db_mysql.c

@@ -42,6 +42,7 @@
  */
 
 #include "../../sr_module.h"
+#include "../../dprint.h"
 #include "km_dbase.h"
 #include "km_db_mysql.h"
 

modules/db_mysql/my_cmd.c

@@ -44,6 +44,7 @@
 #include "../../str.h"
 #include "../../lib/srdb2/db_cmd.h"
 #include "../../ut.h"
+#include "../../dprint.h"
 
 #include <strings.h>
 #include <stdio.h>

modules/db_mysql/mysql_mod.c

@@ -47,6 +47,7 @@
 
 #include "../../sr_module.h"
 #include "../../lib/srdb2/db.h"
+#include "../../dprint.h"
 
 int my_ping_interval = 5 * 60; /* Default is 5 minutes */
 unsigned int my_connect_to = 2; /* 2 s by default */