Fix build after LibreSSL const change.

devel/ptlib/patches/patch-src_ptclib_pssl_cxx

@@ -1,6 +1,16 @@
-$OpenBSD: patch-src_ptclib_pssl_cxx,v 1.3 2015/07/18 21:54:04 sthen Exp $
---- src/ptclib/pssl.cxx.orig	Sat Jul 18 15:51:09 2015
-+++ src/ptclib/pssl.cxx	Sat Jul 18 15:53:02 2015
+$OpenBSD: patch-src_ptclib_pssl_cxx,v 1.4 2018/05/30 00:23:12 tb Exp $
+Index: src/ptclib/pssl.cxx
+--- src/ptclib/pssl.cxx.orig
++++ src/ptclib/pssl.cxx
+@@ -145,7 +145,7 @@ PFACTORY_CREATE_SINGLETON(PProcessStartupFactory, PSSL
+ class PSSL_BIO
+ {
+   public:
+-    PSSL_BIO(BIO_METHOD *method = BIO_s_file_internal())
++    PSSL_BIO(const BIO_METHOD *method = BIO_s_file_internal())
+       { bio = BIO_new(method); }
+ 
+     ~PSSL_BIO()
 @@ -1189,9 +1189,12 @@ void PSSLContext::Construct(Method method, const void 
    SSL_METHOD * meth;