Make Docker host networking safer

The current instructions for I2P in Docker result in either an unsafe local router (the "quick-try" mode) or a firewalled router otherwise. This MR changes all interfaces from 0.0.0.0 to 127.0.0.1 and updates the instructions with some recommendations for cloud deployments.

docker/rootfs/i2p/clients.config

@@ -30,7 +30,7 @@
 ## non-SSL and SSL
 #clientApp.0.args=7657 ::1,127.0.0.1 -s 7667 ::1,127.0.0.1 ./webapps/
 ## non-SSL only, both IPv6 and IPv4 local interfaces
-clientApp.0.args=7657 0.0.0.0 ./webapps/
+clientApp.0.args=7657 127.0.0.1 ./webapps/
 clientApp.0.main=net.i2p.router.web.RouterConsoleRunner
 clientApp.0.name=webConsole
 clientApp.0.onBoot=true
@@ -38,7 +38,7 @@ clientApp.0.onBoot=true
 # start up the SAM bridge so other client apps can connect
 clientApp.1.main=net.i2p.sam.SAMBridge
 clientApp.1.name=SAMBridge
-clientApp.1.args=sam.keys 0.0.0.0 7656 i2cp.tcp.host=localhost i2cp.tcp.port=7654
+clientApp.1.args=sam.keys 127.0.0.1 7656 i2cp.tcp.host=localhost i2cp.tcp.port=7654
 clientApp.1.startOnLoad=false
 
 # poke the i2ptunnels defined in i2ptunnel.config