Revert "Return correct client library version number instead of"

In MariaDB Server 10.3.38
(https://github.com/MariaDB/server/tree/mariadb-10.3.38) with submodule
libmariadb @ d204e83 the file libmariadb/mariadb_lib.c has function
mysql_get_client_version() which emits the wrong version, or at least a
completely different version than what it had been doing for the past 8
years.

This was because of commit made on January 2023 (d204e83).

This caused some consumers of the library to start failing. The issue with
libqt5sql5-mysql failing was reported in https://bugs.debian.org/1031863.

Libraries *must* have a stable ABI, including the version they advertise. If a
library changes behaviour in a backwards incompatible manner, even if it is to
fix a bug, it should bump the version and not just silently get shipped.

This reverts commit d204e83 to put back
as it existed in MariaDB Server 10.3.37 and earlier.

libmariadb/mariadb_lib.c

@@ -3881,7 +3881,7 @@ int STDCALL mysql_set_server_option(MYSQL *mysql,
 
 ulong STDCALL mysql_get_client_version(void)
 {
-  return MARIADB_PACKAGE_VERSION_ID;
+  return MARIADB_VERSION_ID;
 }
 
 ulong STDCALL mysql_hex_string(char *to, const char *from, unsigned long len)