Redis test port allocation fixed.

tests/test_helper.tcl

@@ -153,9 +153,9 @@ proc cleanup {} {
 proc find_available_port start {
     for {set j $start} {$j < $start+1024} {incr j} {
         if {[catch {
-            set fd [socket 127.0.0.1 $start]
+            set fd [socket 127.0.0.1 $j]
         }]} {
-            return $start
+            return $j
         } else {
             close $fd
         }