log.showSignature causes reword dialog to spill gpg info into the commit message

**Describe the bug**
If you enable log.showSignature in `.gitconfig`, lazygit will spill some of the gpg signing info from the commit log into the reword dialog.

**To Reproduce**
Steps to reproduce the behavior:

1. Edit and append the following to `$HOME/.gitconfig`:
```
[log]
showSignature = true
```
2. Open lazygit in some repo with signed commits
3. Select a signed commit, and press `r` to reword
4. Observe how the gpg information gets spilled into the commit message

**Expected behavior**
The gpg information does not get spilled into the reword dialog.

**Screenshots**

**Version info:**
commit=, build date=, build source=unknown, version=0.41.0, os=linux, arch=amd64, git version=2.43.2
git version 2.43.2