Allow passing custom ciphers via options (#1435)

src/App.h

@@ -76,6 +76,7 @@ namespace uWS {
         const char *passphrase = nullptr;
         const char *dh_params_file_name = nullptr;
         const char *ca_file_name = nullptr;
+        const char *ssl_ciphers = nullptr;
         int ssl_prefer_low_memory_usage = 0;
 
         /* Conversion operator used internally */