libressl: OCSP and intermediate certs workaround no longer needed

lib/vtls/openssl.c has a workaround for a bug with OCSP responses signed
by intermediate certs, this was fixed in LibreSSL in
https://github.com/libressl-portable/openbsd/commit/912c64f68f7ac4f225b7d1fdc8fbd43168912ba0

Bug: https://curl.haxx.se/mail/lib-2017-06/0038.html
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 9def5ab..dbee369 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -1371,7 +1371,8 @@
   st = SSL_CTX_get_cert_store(connssl->ctx);
 
 #if ((OPENSSL_VERSION_NUMBER <= 0x1000201fL) /* Fixed after 1.0.2a */ || \
-     defined(LIBRESSL_VERSION_NUMBER))
+     (defined(LIBRESSL_VERSION_NUMBER) &&                               \
+      LIBRESSL_VERSION_NUMBER <= 0x2040200fL))
   /* The authorized responder cert in the OCSP response MUST be signed by the
      peer cert's issuer (see RFC6960 section 4.2.2.2). If that's a root cert,
      no problem, but if it's an intermediate cert OpenSSL has a bug where it