Raise typha max connections to 300 (#5527)

Raises limit from 100 to 300 because the default is far too low
and the pod can handle 300 with the given resources.

Change-Id: Ib1eec10da3d09d198933fcfe87291587e58d7cdb

inventory/sample/group_vars/k8s-cluster/k8s-net-calico.yml

@@ -40,5 +40,9 @@
 # Generate TLS certs for secure typha<->calico-node communication
 # typha_secure: false
 
+# Scaling typha: 1 replica per 100 nodes is adequate
 # Number of typha replicas
 # typha_replicas: 1
+
+# Set max typha connections
+# typha_max_connections_lower_limit: 300