openssl: cleanup must free compression methods

- Free compression methods if OpenSSL 1.0.2 to avoid a memory leak.

Bug: https://github.com/curl/curl/issues/817
Reported-by: jveazey@users.noreply.github.com

lib/vtls/openssl.c

@@ -747,6 +747,11 @@ void Curl_ossl_cleanup(void)
 
   /* Free all memory allocated by all configuration modules */
   CONF_modules_free();
+
+#if OPENSSL_VERSION_NUMBER >= 0x10002003L && \
+    OPENSSL_VERSION_NUMBER <= 0x10002FFFL
+  SSL_COMP_free_compression_methods();
+#endif
 }
 
 /*