Editorial: Use valid UUID in blob: URL example (#151)

The algorithm for creating a blob URL references RFC4122 to generate a UUID. However the example contains an _invalid_ UUID (according to RFC4122): 9115d58c-bcda-ff47-86e5-083e9a215304

This given string is not a valid UUID because it does not contain a meaningful version field (the first character after the second dash).

Author: ctavan

index.bs

@@ -1499,7 +1499,7 @@ generate a new blob URL</dfn>, run the following steps:
 
 <div class="example">
   An example of a blob URL that can be generated by this algorithm is
-  `blob:https://example.org/9115d58c-bcda-ff47-86e5-083e9a215304`1.
+  `blob:https://example.org/40a5fb5a-d56d-4a33-b4e2-0acf6a8e5f64`1.
 </div>
 
 <div algorithm="addBlobURL">