Revert "fix(calico): Force good MTU"

Turns out the problem was based in the wiretrustee usage, that confused
calico, resulting in double-tunneling.

This reverts commit 8a519732.

bootstrap/calico/release.yaml

@@ -24,7 +24,6 @@ spec:
       calicoNetwork:
         bgp: Enabled
         hostPorts: Enabled
-        mtu: 1440
         ipPools:
           - blockSize: 26
             cidr: 10.1.0.0/16