Update link to license in Docs.gmk

Due to changes in the server hosting the Spec license redirect, we must use a new URL in JDK 16 which omits the "technetwork" token. The following link for 16 is now live:

    https://www.oracle.com/java/javase/terms/license/java16speclicense.html

The LICENSE_URL for the JavaDoc API Specification should be updated to reference the 16 license as follows:

diff -r ff4c9c270e3f make/Docs.gmk
--- a/make/Docs.gmk Mon Jun 08 20:24:29 2020 -0400
+++ b/make/Docs.gmk Mon Jun 08 19:09:51 2020 -0700
@@ -63,7 +63,7 @@
 JAVADOC_BASE_URL := https://docs.oracle.com/pls/topic/lookup?ctx=javase$(VERSION_NUMBER)&id=homepage
 BUG_SUBMIT_URL := https://bugreport.java.com/bugreport/
 COPYRIGHT_URL := legal/copyright.html
-LICENSE_URL := https://www.oracle.com/technetwork/java/javase/terms/license/java$(VERSION_NUMBER)speclicense.html
+LICENSE_URL := https://www.oracle.com/java/javase/terms/license/java$(VERSION_NUMBER)speclicense.html
 REDISTRIBUTION_URL := https://www.oracle.com/technetwork/java/redist-137594.html

 # In order to get a specific ordering it's necessary to specify the total