internal/debug: also rename debug_startTrace to debug_startGoTrace

This was missing from the previous change.

internal/debug/trace_fallback.go

@@ -22,10 +22,10 @@ package debug
 
 import "errors"
 
-func (*HandlerT) StartTrace(string) error {
+func (*HandlerT) StartGoTrace(string) error {
 	return errors.New("tracing is not supported on Go < 1.5")
 }
 
-func (*HandlerT) StopTrace() error {
+func (*HandlerT) StopGoTrace() error {
 	return errors.New("tracing is not supported on Go < 1.5")
 }