New upstream version 2.12.3

bom/pom.xml

client/pom.xml

...lient/netty/handler/intercept/Redirect30xInterceptor.java

...rg/asynchttpclient/netty/request/NettyRequestFactory.java

...org/asynchttpclient/netty/request/NettyRequestSender.java

.../src/main/java/org/asynchttpclient/proxy/ProxyServer.java

...test/java/org/asynchttpclient/AsyncStreamHandlerTest.java

...t/java/org/asynchttpclient/BasicHttpProxyToHttpsTest.java

client/src/test/java/org/asynchttpclient/Head302Test.java

...src/test/java/org/asynchttpclient/MultipleHeaderTest.java

...asynchttpclient/netty/NettyConnectionResetByPeerTest.java

...java/org/asynchttpclient/proxy/CustomHeaderProxyTest.java

example/pom.xml

extras/guava/pom.xml

extras/jdeferred/pom.xml

extras/pom.xml

extras/registry/pom.xml

extras/retrofit2/pom.xml

extras/rxjava/pom.xml

extras/rxjava2/pom.xml