SAK-40434 Fix off-by-one error in isLarge check (sakaiproject#5869)

Gradebook uses two different serialization schemes, depending on the
size of the maximum grade that needs to be represented.  The boundary
between these schemes (16384) wasn't properly handled: it would
attempt to use packed serialization but then throw an error because
the value couldn't be represented.

gradebookng/tool/src/java/org/sakaiproject/gradebookng/tool/model/GbGradebookData.java

@@ -620,7 +620,7 @@ public boolean isNull() {
 		}
 
 		public boolean isLarge() {
-			return score != null && Double.valueOf(score) > 16384;
+			return score != null && Double.valueOf(score) >= 16384;
 		}
 
         public boolean isExcused() {