tests/tls: Disable checks for ALPN on apple platforms

On Apple platforms, ALPN does not work as securetransport does
not provide any public API for that. So do not check for that
feature until support is added.

test/modules/misc/tls.c

@@ -201,9 +201,13 @@ int main(void)
     answer = 1;
     val = securepair(&th, &tls, alpnv, &alp);
     assert(val == 0);
+
+    /* SecureTransport, used on apple platforms, does not support ALPN */
+#ifndef __APPLE__
     assert(alp != NULL);
     assert(!strcmp(alp, "bar"));
     free(alp);
+#endif
 
     /* Do some I/O */
     char buf[12];