package-lock.json: run npm audit fix
package-lock.json: run npm audit fix

Even though I thought I had just done this, when I ran all.bash,
npm audit complained. This CL is the result of running

    ./all.bash npm audit fix

Change-Id: I00f4d8059bb9f44ba97a3e0118d40216eea08060
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/413034
Run-TryBot: Jonathan Amsterdam <e3d3698b2ccd5955e4adf250d0785062d0f9018b@google.com>
Reviewed-by: Jamal Carvalho <e0195770807aa8c82b0b128d9c0423b5ad035172@golang.org>
TryBot-Result: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

golang/pkgsite,golang/pkgsite,golang/pkgsite,golang/pkgsite