gopls/doc/troubleshooting.md: update the gopls output channel name

Since v0.15.0, VS Code Go extension uses the `gopls (server)` channel
for the server-side logging.

Change-Id: I6dc2125af59562576d20e29a0801be6b4ce394bb
Reviewed-on: https://go-review.googlesource.com/c/tools/+/240677
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
diff --git a/gopls/doc/troubleshooting.md b/gopls/doc/troubleshooting.md
index faadf4a..e9b21ef 100644
--- a/gopls/doc/troubleshooting.md
+++ b/gopls/doc/troubleshooting.md
@@ -35,7 +35,7 @@
 
 #### VS Code
 
-For VSCode users, the gopls log can be found by navigating to `View` -> `Output` (or `Ctrl+K Ctrl+H`). There will be a drop-down menu titled `Tasks` in the top-right corner. Select the `gopls` item, which will contain the `gopls` logs.
+For VSCode users, the gopls log can be found by navigating to `View` -> `Output` (or `Ctrl+K Ctrl+H`). There will be a drop-down menu titled `Tasks` in the top-right corner. Select the `gopls (server)` item, which will contain the `gopls` logs.
 
 To increase the level of detail in your logs, add the following to your VS Code settings: