Consolidate kube-proxy module and sysctl loading (#1586)

This sets br_netfilter and net.bridge.bridge-nf-call-iptables sysctl from a single play before kube-proxy is first ran instead of from the flannel and weave network_plugin roles after kube-proxy is started

roles/network_plugin/weave/tasks/main.yml

@@ -4,18 +4,6 @@
 - include: seed.yml
   when: weave_mode_seed
 
-- name: Weave | Verify if br_netfilter module exists
-  shell: "modinfo br_netfilter"
-  register: modinfo_br_netfilter
-  failed_when: modinfo_br_netfilter.rc not in [0, 1]
-  changed_when: false
-
-- name: Weave | Enable br_netfilter module
-  modprobe:
-    name: br_netfilter
-    state: present
-  when: modinfo_br_netfilter.rc == 0
-
 - name: Weave | Copy cni plugins from hyperkube
   command: "{{ docker_bin_dir }}/docker run --rm -v /opt/cni/bin:/cnibindir {{ hyperkube_image_repo }}:{{ hyperkube_image_tag }} /bin/cp -r /opt/cni/bin/. /cnibindir/"
   register: cni_task_result