gitstamp-action@v1 crashes when commit message is not set

[humaite]

Hi there,

While using weavery/gitstamp-action@v1 on our side, it happens our pipeline is failing with this error:

Run weavery/gitstamp-action@v1
  with:
    wallet-key: ***
    commit-link: true
Include a commit link: true
The HEAD commit: undefined
Error: TypeError: Cannot read properties of undefined (reading 'message')
Trace
    at run (/home/runner/work/_actions/weavery/gitstamp-action/v1/index.js:4[2](https://github.com/ArweaveTeam/arweave/actions/runs/12990065342/job/36224395211#step:3:2):13)
    at Object.<anonymous> (/home/runner/work/_actions/weavery/gitstamp-action/v1/index.js:46:1)
    at Module._compile (node:internal/modules/cjs/loader:1469:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1548:10)
    at Module.load (node:internal/modules/cjs/loader:1288:[3](https://github.com/ArweaveTeam/arweave/actions/runs/12990065342/job/36224395211#step:3:3)2)
    at Module._load (node:internal/modules/cjs/loader:110[4](https://github.com/ArweaveTeam/arweave/actions/runs/12990065342/job/36224395211#step:3:4):12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:1[7](https://github.com/ArweaveTeam/arweave/actions/runs/12990065342/job/36224395211#step:3:8)4:12)
    at node:internal/main/run_main_module:28:49

This action is usually working fine.

[humaite]

This bug can be reproduced by creating a commit with only one line (a title), example:

here my commit

When adding more than one line, everything looks fine.

here my commit

here the content of the message

If the message is empty, the title should probably be used instead of crashing, or set message to an empty string?