package/libkrb5: doesn't build with libressl

libkrb5 does not build with libressl since commit
b7a5b9d06d484700fc4fcbd354f2c15e0422688c and upstream is not interested
in fixing this issue as a PR is opened for more than 4 years
(https://github.com/krb5/krb5/pull/607):

pkinit_crypto_openssl.c: In function 'cms_signeddata_verify':
pkinit_crypto_openssl.c:1700:22: error: implicit declaration of function 'OBJ_get0_data'; did you mean 'BIO_get_data'? [-Werror=implicit-function-declaration]
 1700 |         print_buffer(OBJ_get0_data(etype), OBJ_length(etype));
      |                      ^~~~~~~~~~~~~
      |                      BIO_get_data

Fixes:
 - http://autobuild.buildroot.org/results/e623f4e1d6b6004e98815b8b7da3938238890bd8

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Reviewed-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/libkrb5/libkrb5.mk

@@ -49,7 +49,7 @@ else
 LIBKRB5_CONF_OPTS += --without-ldap
 endif
 
-ifeq ($(BR2_PACKAGE_OPENSSL),y)
+ifeq ($(BR2_PACKAGE_LIBOPENSSL),y)
 LIBKRB5_CONF_OPTS += \
 	--enable-pkinit \
 	--with-crypto-impl=openssl \