Update nginx to 1.13.10 and enable gRPC

[aledbf]

Starting point to add gRPC support #2207

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• images/OWNERS [aledbf]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov-io]

Codecov Report

Merging #2221 into master will decrease coverage by 0.14%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2221      +/-   ##
==========================================
- Coverage   37.12%   36.98%   -0.15%     
==========================================
  Files          70       70              
  Lines        4978     4978              
==========================================
- Hits         1848     1841       -7     
- Misses       2851     2857       +6     
- Partials      279      280       +1

Impacted Files	Coverage Δ
cmd/nginx/main.go	21.37% <0%> (-4.83%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update df00b03...fdbf7e4. Read the comment docs.