gopls/internal/lsp/cache: tweak error message

Change-Id: I0dacb32e76b0e657d1e0893f71da8f1ce38b7d50
Reviewed-on: https://go-review.googlesource.com/c/tools/+/496441
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
diff --git a/gopls/internal/lsp/cache/snapshot.go b/gopls/internal/lsp/cache/snapshot.go
index 64e1b55..7567589 100644
--- a/gopls/internal/lsp/cache/snapshot.go
+++ b/gopls/internal/lsp/cache/snapshot.go
@@ -1833,7 +1833,7 @@
 					fix = `To work with multiple modules simultaneously, please upgrade to Go 1.18 or
 later, reinstall gopls, and use a go.work file.`
 				}
-				msg = fmt.Sprintf(`This file is in directory %q, which is not included in your workspace.
+				msg = fmt.Sprintf(`This file is within module %q, which is not included in your workspace.
 %s
 See the documentation for more information on setting up your workspace:
 https://github.com/golang/tools/blob/master/gopls/doc/workspace.md.`, modDir, fix)