Fix FTLDNS link in docker page

The old link was pointing to a non existent page, removed some time ago.

Signed-off-by: RD WebDesign <[email protected]>

Author: rdwebdesign

docs/docker/index.md

@@ -55,7 +55,7 @@ docker run --name pihole -p 53:53/tcp -p 53:53/udp -p 80:80/tcp -p 443:443/tcp -
 
 ## Note On Capabilities
 
-[FTLDNS](https://docs.pi-hole.net/ftldns/in-depth/#linux-capabilities) expects to have the following capabilities available:
+[FTLDNS](https://docs.pi-hole.net/ftldns/) expects to have the following capabilities available:
 
 - `CAP_NET_BIND_SERVICE`: Allows FTLDNS binding to TCP/UDP sockets below 1024 (specifically DNS service on port 53)
 - `CAP_NET_RAW`: use raw and packet sockets (needed for handling DHCPv6 requests, and verifying that an IP is not in use before leasing it)