remove additional references

Author: kbahr

build.gradle

@@ -55,7 +55,6 @@ subprojects {
     ext['zipkin.sender.version'] = '2.7.6'
     ext['hdrhistogram.version'] = '2.1.10'
     ext['netty.version'] = '4.1.29.Final'
-    ext['netty-tcnative.version'] = '2.0.18.Final'
     ext['typesafe-config.version'] = '1.3.3'
 
     sourceCompatibility = 1.8

proteus-client/build.gradle

@@ -10,7 +10,6 @@ dependencies {
     compile 'com.typesafe:config'
     compile 'com.google.guava:guava'
     compile 'io.rsocket.rpc:rsocket-rpc-core'
-    compile "io.netty:netty-tcnative:${ext['netty-tcnative.version']}:linux-x86_64"
 
     testProtobuf 'io.rsocket.rpc:rsocket-rpc-protobuf-idl'
     testCompile project(':proteus-tracing-openzipkin')