Include MariaDB Connector-C headers first

The MariaDB Connector-C headers that are built by MaxScale must be
included before any system headers.

Fixed code that explicitly included the <mysql.h> header to use the
<maxscale/protocol/mysql.h> wrapper instead.

CMakeLists.txt

@@ -50,6 +50,7 @@ find_package(ASAN)
 include(cmake/BuildPCRE2.cmake)
 
 include_directories(BEFORE ${PCRE2_INCLUDE_DIRS})
+include_directories(BEFORE ${MARIADB_CONNECTOR_INCLUDE_DIR})
 
 # If the connector was not found, download and build it from source
 if(NOT MARIADB_CONNECTOR_FOUND)

include/maxscale/monitor.h

@@ -18,13 +18,13 @@
 
 #include <maxscale/cdefs.h>
 
-#include <mysql.h>
 #include <openssl/sha.h>
 
 #include <maxscale/config.h>
 #include <maxscale/dcb.h>
 #include <maxscale/server.h>
 #include <maxscale/jansson.h>
+#include <maxscale/protocol/mysql.h>
 
 MXS_BEGIN_DECLS
 

include/maxscale/mysql_utils.h

@@ -15,7 +15,7 @@
 #include <maxscale/cdefs.h>
 #include <stdlib.h>
 #include <stdint.h>
-#include <mysql.h>
+#include <maxscale/protocol/mysql.h>
 #include <maxscale/server.h>
 
 MXS_BEGIN_DECLS