fix(utils): resolve undefined observable

[dai-shi]

close #760

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[github-actions]

Size Change: +28 B (0%)

Total Size: 37.3 kB

Filename	Size	Change
dist/esm/utils.js	4.26 kB	+5 B (0%)
dist/utils.js	5.21 kB	+23 B (0%)

ℹ️ View Unchanged

Filename	Size
dist/babel/plugin-debug-label.js	794 B
dist/babel/preset.js	819 B
dist/devtools.js	1.56 kB
dist/esm/babel/plugin-debug-label.js	622 B
dist/esm/babel/preset.js	648 B
dist/esm/devtools.js	1.4 kB
dist/esm/immer.js	592 B
dist/esm/index.js	4.22 kB
dist/esm/optics.js	640 B
dist/esm/query.js	1.25 kB
dist/esm/redux.js	251 B
dist/esm/urql.js	1.43 kB
dist/esm/valtio.js	512 B
dist/esm/xstate.js	947 B
dist/esm/zustand.js	284 B
dist/immer.js	729 B
dist/index.js	5.13 kB
dist/optics.js	935 B
dist/query.js	1.36 kB
dist/redux.js	314 B
dist/urql.js	1.48 kB
dist/valtio.js	575 B
dist/xstate.js	1.04 kB
dist/zustand.js	344 B

_{compressed-size-action}

[dai-shi]

https://codesandbox.io/s/react-typescript-forked-forked-pbue6
Fixed! cc @ricmello