Make CI binaries slightly smaller

Disables symbol table and DWARF generation. Stack traces and other runtime
debugging features should still work, only external tools like gdb won't.

.gitlab-ci.yml

@@ -12,7 +12,7 @@ stages:
   - mkdir -p .cache
   - export GOPATH="$CI_PROJECT_DIR/.cache"
   - export GOCACHE="$CI_PROJECT_DIR/.cache/build"
-  - export GO_LDFLAGS="-linkmode external -extldflags -static -X main.Tag=$CI_COMMIT_TAG -X main.Commit=$CI_COMMIT_SHA -X 'main.BuildTime=`date '+%b %_d %Y, %H:%M:%S'`'"
+  - export GO_LDFLAGS="-s -w -linkmode external -extldflags -static -X main.Tag=$CI_COMMIT_TAG -X main.Commit=$CI_COMMIT_SHA -X 'main.BuildTime=`date '+%b %_d %Y, %H:%M:%S'`'"
   script:
   - go build -ldflags "$GO_LDFLAGS" -o mautrix-whatsapp
   artifacts: