[infra] Fix co19 git URL in DEPS

TBR=whesse@google.com

Change-Id: I67e4b8ccfb3fad7fac1a83ac998dc23c72cfee08
Reviewed-on: https://dart-review.googlesource.com/c/90067
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Alexander Thomas <athom@google.com>
diff --git a/DEPS b/DEPS
index 0018973..2df2e7c 100644
--- a/DEPS
+++ b/DEPS
@@ -177,7 +177,7 @@
   },
 
   Var("dart_root") + "/tests/co19_2/src":
-      Var("dart_git") + "/co19.git" +
+      Var("dart_git") + "co19.git" +
       "@" + Var("co19_2_rev"),
 
   Var("dart_root") + "/third_party/zlib":