Fix max index define that was not updated

In PR #29145 a new OSSL_LIB_CTX_SSL_CONF_IMODULE was added, but
the OSSL_LIB_CTX_MAX_INDEXES value was left behind.

This should probably be converted to an enum, but I'll leave that work
to some other brave soul.

Signed-off-by: Simo Sorce <simo@redhat.com>

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Eugene Syromiatnikov <esyr@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/29581)

include/internal/cryptlib.h

@@ -117,8 +117,8 @@ typedef struct ossl_ex_data_global_st {
 #define OSSL_LIB_CTX_DECODER_CACHE_INDEX 20
 #define OSSL_LIB_CTX_COMP_METHODS 21
 #define OSSL_LIB_CTX_INDICATOR_CB_INDEX 22
-#define OSSL_LIB_CTX_MAX_INDEXES 22
 #define OSSL_LIB_CTX_SSL_CONF_IMODULE 23
+#define OSSL_LIB_CTX_MAX_INDEXES 23
 
 OSSL_LIB_CTX *ossl_lib_ctx_get_concrete(OSSL_LIB_CTX *ctx);
 int ossl_lib_ctx_is_default(OSSL_LIB_CTX *ctx);