MXS-2197: Make config.h and service.h C++ headers

This is the first step into converting the other headers into C++.

server/modules/authenticator/GSSAPI/GSSAPIAuth/gssapi_auth.cc

@@ -22,7 +22,7 @@
 #include <maxscale/mysql_utils.h>
 #include <maxscale/protocol/mysql.h>
 #include <maxscale/secrets.h>
-#include <maxscale/service.h>
+#include <maxscale/service.hh>
 #include <maxscale/sqlite3.h>
 #include <maxscale/users.h>
 

server/modules/authenticator/HTTPAuth/http_auth.cc

@@ -32,7 +32,7 @@
 #include <maxscale/dcb.h>
 #include <maxscale/buffer.h>
 #include <openssl/bio.h>
-#include <maxscale/service.h>
+#include <maxscale/service.hh>
 #include <maxscale/secrets.h>
 #include <maxscale/users.h>
 

server/modules/authenticator/MySQLAuth/dbusers.cc

@@ -31,7 +31,7 @@
 #include <maxscale/pcre2.h>
 #include <maxscale/router.h>
 #include <maxscale/secrets.h>
-#include <maxscale/service.h>
+#include <maxscale/service.hh>
 #include <maxscale/users.h>
 #include <maxscale/utils.h>
 

server/modules/authenticator/MySQLAuth/mysql_auth.h

@@ -32,7 +32,7 @@
 #include <maxscale/authenticator.h>
 #include <maxscale/dcb.h>
 #include <maxscale/buffer.h>
-#include <maxscale/service.h>
+#include <maxscale/service.hh>
 #include <maxscale/sqlite3.h>
 #include <maxscale/protocol/mysql.h>
 

server/modules/authenticator/PAM/PAMAuth/pam_instance.hh

@@ -14,7 +14,7 @@
 #include "pam_auth.hh"
 
 #include <string>
-#include <maxscale/service.h>
+#include <maxscale/service.hh>
 #include <maxscale/sqlite3.h>
 
 /** The instance class for the client side PAM authenticator, created in pam_auth_init() */