internal/lsp: split only on the first = for Go environment variables

Follow-up from CL 243538.

Change-Id: I15ac8ba738fa5326b18f7b179bed8623f4c57cfd
Reviewed-on: https://go-review.googlesource.com/c/tools/+/243640
Run-TryBot: Rebecca Stambler <[email protected]>
Reviewed-by: Heschi Kreinick <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

internal/lsp/cache/view.go

@@ -350,7 +350,7 @@ func (v *View) WriteEnv(ctx context.Context, w io.Writer) error {
 		fullEnv[k] = v
 	}
 	for _, v := range env {
-		s := strings.Split(v, "=")
+		s := strings.SplitN(v, "=", 2)
 		if len(s) != 2 {
 			continue
 		}