Update ZNC to v1.6.1

And also restructure the Dockerfile a bit.

znc.conf.default

@@ -8,27 +8,27 @@
 // But if you feel risky, you might want to read help on /znc saveconfig and /znc rehash.
 // Also check http://en.znc.in/wiki/Configuration
 
-Version = 1.4
+Version = 1.6.1
 <Listener l>
-	Port = 6667
-	IPv4 = true
-	IPv6 = true
-	SSL = false
+        Port = 6667
+        IPv4 = true
+        IPv6 = true
+        SSL = false
 </Listener>
 LoadModule = webadmin
 
 <User admin>
-	Pass       = sha256#1b9a69be60544ae4a83147ebb04c4c1edc24dba4c62f8f25ef5603b06c264476#5zD6V:PYLf*jZcL8VbZY#
-	Admin      = true
-	Nick       = admin
-	AltNick    = admin_
-	Ident      = admin
-	RealName   = Got ZNC?
-	Buffer     = 50
-	AutoClearChanBuffer = true
-	ChanModes  = +stn
+        Pass       = sha256#00793765305dfc3e7bba28267fe9d9e2c721ebef4e20f3a89720265a89ee6a4f#N!lgZM8S.HZ4zH?)vFoW#
+        Admin      = true
+        Nick       = admin
+        AltNick    = admin_
+        Ident      = admin
+        RealName   = Got ZNC?
+        Buffer     = 50
+        AutoClearChanBuffer = true
+        ChanModes  = +stn
 
-	LoadModule = chansaver
-	LoadModule = controlpanel
-	LoadModule = perform
+        LoadModule = chansaver
+        LoadModule = controlpanel
+        LoadModule = perform
 </User>