_content/doc/go1.17: fix sentence about ARM64 frame pointers

Updates golang/go#44513

Change-Id: Idb5c85e7a641e1a58dad46bcf1adc6c8f6fd13b7
Reviewed-on: https://go-review.googlesource.com/c/website/+/347849
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>

_content/doc/go1.17.html

@@ -115,8 +115,8 @@ <h3 id="arm64">ARM64</h3>
 
 <p><!-- CL 288814 -->
  Go programs now maintain stack frame pointers on the 64-bit ARM
- architecture on all operating systems. Previously it maintained
- stack frame pointers only on Linux, macOS, and iOS.
+ architecture on all operating systems. Previously, stack frame
+ pointers were only enabled on Linux, macOS, and iOS.
 </p>
 
 <h3 id="loong64">loong64 GOARCH value reserved</h3>