minor #10363 default redis port (tmihalik)

This PR was submitted for the 4.1 branch but it was merged into the 3.4 branch instead (closes #10363).

Discussion
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default redis port

the default redis port is 6379

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Commits
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e76cf18 Update redis_adapter.rst

Author: javiereguiluz

components/cache/adapters/redis_adapter.rst

@@ -92,7 +92,7 @@ array of ``key => value`` pairs representing option names and their respective v
     $client = RedisAdapter::createConnection(
 
         // provide a string dsn
-        'redis://localhost:6739',
+        'redis://localhost:6379',
 
         // associative array of configuration options
         array(