opensips-1.11.8-1.fc26 fails to build in F26:

gcc -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -m64 -mtune=generic -fgnu89-inline -Wcast-align  -I/usr/include/json-c -DPKG_MALLOC  -DSHM_MEM  -DSHM_MMAP  -DUSE_IPV6  -DUSE_MCAST  -DDISABLE_NAGLE  -DSTATISTICS  -DCHANGEABLE_DEBUG_LEVEL  -DHAVE_RESOLV_RES  -DF_MALLOC  -DUSE_TCP   -DNAME='"opensips"' -DVERSION='"1.11.8-tls"' -DARCH='"x86_64"' -DOS='"linux"' -DCOMPILER='"gcc 6.2.1"' -D__CPU_x86_64 -D__OS_linux -D__SMP_yes -DCFG_DIR='"/etc/opensips/"'  -DUSE_FREERADIUS -DUSE_TLS -DFAST_LOCK -DADAPTIVE_WAIT -DADAPTIVE_WAIT_LOOPS=1024  -DHAVE_GETHOSTBYNAME2 -DHAVE_UNION_SEMUN -DHAVE_SCHED_YIELD -DHAVE_MSG_NOSIGNAL -DHAVE_MSGHDR_MSG_CONTROL -DHAVE_ALLOCA_H -DHAVE_TIMEGM -DHAVE_EPOLL -DHAVE_SIGIO_RT -DHAVE_SELECT -I/usr/ssl/include -I/usr/include -I/usr/include/openssl -c tls/tls_server.c -o tls/tls_server.o
[...]
tls/tls_server.c: In function 'tls_accept':
tls/tls_server.c:232:10: error: dereferencing pointer to incomplete type 'SSL {aka struct ssl_st}'
  if ( ssl->kssl_ctx==NULL )
          ^~

This is caused by upgrading openssl from 1:1.0.2j-1.fc26 to 1:1.1.0b-1.fc26.