Add missing module required dependency on netty-codec-http and remove generated files.

Author: vietj

src/main/generated/io/vertx/httpproxy/ProxyOptionsConverter.java

@@ -3,6 +3,7 @@
   requires io.vertx.core.logging;
   requires static io.vertx.codegen.api;
   requires static io.vertx.codegen.json;
+  requires io.netty.codec.http;
   requires static vertx.docgen;
   exports io.vertx.httpproxy;
   exports io.vertx.httpproxy.cache;