fix(zipimage): set mimetype to text plain when undetectable

Signed-off-by: John Andersen <johnandersen777@protonmail.com>

README.md

@@ -2,12 +2,18 @@
 
 GitHub: https://github.com/publicdomainrelay/atprotobin
 
-Paste
+Paste file
 
 ```bash
 curl -X POST -F file=@README.md https://paste.chadig.com
 ```
 
+Paste from clipboard (linux with xclip)
+
+```bash
+curl -X POST -F file=@<(xclip) https://paste.chadig.com
+```
+
 Retrive using id from paste reponse JSON (`| jq -r .id`)
 
 ```bash

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "atprotobin"
-version = "1.1.0"
+version = "1.1.1"
 description = "ATProto based pastebin"
 readme = {file = "README.md", content-type = "text/markdown"}
 authors = [

src/atprotobin/zip_image.py

@@ -16,6 +16,8 @@ def create_zip_of_files(file_contents, file_name: str = None):
             mimetype = mimetypes.guess_file_type(file_name)
         else:
             mimetype, _encoding = mimetypes.guess_type(file_name)
+    if mimetype is None:
+        mimetype = "text/plain"
     with zipfile.ZipFile(zip_buffer, 'w', zipfile.ZIP_DEFLATED) as zipf:
         zipf.writestr(mimetype, file_contents)
     zip_buffer.seek(0)