[roll] Roll antlion Fixup type error in StartStopClientConnectionsTest

This error was caught at compile time when I made an unrelated change
in this file. It's not clear to me how it was successfully compiling
before.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/antlion/+/1338885
Original-Revision: d6ca148549d58962f73a7d9094f92346e0d5bea1
GitOrigin-RevId: e9c613c55f644d47ddbb41adaf45e85e6fe51018
Change-Id: I276d23f7337373aa915979933397c72006bd0335
diff --git a/stem b/stem
index d9e5013..fdcf0f4 100644
--- a/stem
+++ b/stem
@@ -24,6 +24,6 @@
              path="third_party/antlion"
              remote="https://fuchsia.googlesource.com/antlion"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="c99a8af93034579ee24d8d8f0b212d8508b3864d"/>
+             revision="d6ca148549d58962f73a7d9094f92346e0d5bea1"/>
   </projects>
 </manifest>