Fix callsite toString method #230

Job	Run time
check-versions	6s
wasm-pack (linux 64 bits)	6m 35s
static-checks (lint)	22s
test-native (linux 64 bits, ubuntu-latest)	2m 1s
static-checks (clippy)	1m 2s
test-native (windows 64 bits, windows-latest)	4m 12s
test-native (macos 64 bits, macos-latest)	5m 49s
compile-v8-and-run-tests	42m 48s
test-native-js (linux 64 bits, ubuntu-latest, x64)	23s
test-docker (alpine 64 bits, test.alpine.Dockerfile)	33s
test-native-js (windows 64 bits, windows-latest, x64)	1m 5s
test-native-js (windows 32 bits, windows-latest, x86)	49s
test-native-js (macos 64 bits, macos-latest, x64)	46s
all-good	1s
	1h 6m 32s

Provide feedback