Repairing Apache after OpenSSL update

I made an OpenSSL upgrade on ubuntu server (14.04 LTS) via apt to 1.1.0f. After the upgrade was finished, I tried to (re)start apache2. Then this appears:

 * Starting Apache httpd web server apache2
 *
 * The apache2 configtest failed.
Output of config test was:
apache2: Syntax error on line 140 of /etc/apache2/apache2.conf: Syntax error on line 3 of /etc/apache2/mods-enabled/ssl.load: Cannot load /usr/lib/apache2/modules/mod_ssl.so into server: /usr/lib/apache2/modules/mod_ssl.so: symbol X509_getm_notAfter, version OPENSSL_1_1_0 not defined in file libcrypto.so.1.1 with link time reference
Action 'configtest' failed.
The Apache error log may have more information.

But the error.log was empty from the time after the OpenSSL upgrade.

What is causing the error and how do I solve it?