mysql: always use #include <mysql.h>, rely on pkgconfig to get the correct include folder

Author: spytheman

vlib/mysql/_cdefs_nix.c.v

@@ -4,8 +4,8 @@ module mysql
 
 $if $pkgconfig('mysqlclient') {
 	#pkgconfig mysqlclient
-	#include <mysql/mysql.h> # Please install the libmysqlclient-dev development headers
+	#include <mysql.h> # Please install the libmysqlclient-dev development headers
 } $else {
 	#pkgconfig mariadb
-	#include <mariadb/mysql.h> # Please install the libmariadb-dev development headers
+	#include <mysql.h> # Please install the libmariadb-dev development headers
 }