Update Go to 1.16.7

go1.16.7 (released 2021-08-05) includes a security fix to the net/http/httputil
package, as well as bug fixes to the compiler, the linker, the runtime, the go
command, and the net/http package. See the Go 1.16.7 milestone on the issue
tracker for details:

https://github.com/golang/go/issues?q=milestone%3AGo1.16.7+label%3ACherryPickApproved

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

.github/workflows/nightly.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v2
         with:
-          go-version: '1.16.6'
+          go-version: '1.16.7'
 
       - uses: actions/checkout@v2
         with:
@@ -135,7 +135,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v2
         with:
-          go-version: '1.16.6'
+          go-version: '1.16.7'
 
       - uses: actions/checkout@v2
         with: