Remove workaround from gpgme 0.3.x

Currently we depend on gpgme 1.16.x

mimetreeparser/src/messagepart.cpp

@@ -885,11 +885,6 @@ void SignedMessagePart::sigStatusToMetaData()
             // won't trust implicitly the plugin that gave us these data.
             if (key.userID(iMail).email()) {
                 QString email = QString::fromUtf8(key.userID(iMail).email());
-                // ### work around gpgme 0.3.x / cryptplug bug where the
-                // ### email addresses are specified as angle-addr, not addr-spec:
-                if (email.startsWith(QLatin1Char('<')) && email.endsWith(QLatin1Char('>'))) {
-                    email = email.mid(1, email.length() - 2);
-                }
                 if (!email.isEmpty()) {
                     partMetaData()->signerMailAddresses.append(email);
                 }