content/static/html: use the term "redistributable"

Use "redistributable" instead of "permissive" because it is more accurate.

For golang/go##43758

Change-Id: I13b7d11002ba740bc2729133db6579ad31d059ca
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/284234
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Julie Qiu <julie@golang.org>

content/static/html/helpers/_unit_meta.tmpl

@@ -62,8 +62,8 @@
       </li>
       <li>
         {{template "unit_meta_details_check" .Unit.IsRedistributable}}
-        Permissive license
-        {{template "unit_meta_details_toggletip" "Permissive licenses place minimal restrictions on how software can be used, modified, and redistributed."}}
+        Redistributable license
+        {{template "unit_meta_details_toggletip" "Redistributable licenses place minimal restrictions on how software can be used, modified, and redistributed."}}
       </li>
       <li>
         {{template "unit_meta_details_check" .Details.IsTaggedVersion}}