Update MangaPro.kt

[Jack-0009]

fix error

Checklist:

• Updated extVersionCode value in build.gradle for individual extensions
• Updated overrideVersionCode or baseVersionCode as needed for all multisrc extensions
• Referenced all related issues in the PR body (e.g. "Closes #xyz")
• Added the isNsfw = true flag in build.gradle when appropriate
• Have not changed source names
• Have explicitly kept the id if a source's name or language were changed
• Have tested the modifications by compiling and running the extension through Android Studio
• Have removed web_hi_res_512.png when adding a new extension

[Smol-Ame]

• You changed the versionId, not the versionCode in the build.gradle file. Changing the versionId will make it register as a completely separate extension than the current one.
• You didn't reference the relevant requests, put "Closes Manga Pro: No results found, HTTP 404, Unexpected JSON error #10119" in your PR description.
• Mark the relevant checklist items as checked when you've done so
• If you're not finished with your changes, mark the PR as a draft PR or wait until you're finished to submit a PR.

[stevenyomi]

Superseded by #10399