One more forgotten gx reference

ribasushi · ribasushi · commit 4b86611bb3ef · 2020-03-12T06:02:22.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -23,7 +23,6 @@ script:
 
 cache:
   directories:
-    - $GOPATH/src/gx
     - $GOPATH/pkg/mod
     - $HOME/.cache/go-build
 
