Switch back to the GTX 660 bot on the CQ

It seems to be stable after upgrading to Debian 9.

Bug: skia:
Change-Id: I6c89f14748da177c9b0ede8da1da492564e66118
Reviewed-on: https://skia-review.googlesource.com/21361
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
diff --git a/infra/branch-config/cq.cfg b/infra/branch-config/cq.cfg
index 4504f4e..5cdd9ee 100644
--- a/infra/branch-config/cq.cfg
+++ b/infra/branch-config/cq.cfg
@@ -56,7 +56,7 @@
       builders { name: "Housekeeper-PerCommit-InfraTests" }
       builders { name: "Test-Android-Clang-GalaxyS6-GPU-MaliT760-arm64-Release-Android" }
       builders { name: "Test-Debian9-GCC-GCE-CPU-AVX2-x86_64-Debug" }
-      builders { name: "Test-Ubuntu16-Clang-NUC5PPYH-GPU-IntelHD405-x86_64-Release" }
+      builders { name: "Test-Debian9-GCC-ShuttleA-GPU-GTX660-x86_64-Release" }
       builders { name: "Test-Win2k8-MSVC-GCE-CPU-AVX2-x86_64-Release" }
     }
     try_job_retry_config {