Resolve "Bild wird nicht angezeigt"

Closes #36 (closed)

src/textapi.py

 import logging
 import json
 import xml.etree.ElementTree as ET
-from os.path import exists
+from os.path import exists, isfile
 from pathlib import Path
 from fastapi import FastAPI, Request, Response
 from fastapi.middleware.cors import CORSMiddleware
@@ -79,21 +79,19 @@ async def get_css(file_name: str):
         return FileResponse(css_path)
     logging.warning(f'Requested file {file_name}.css not available.')
 
-@app.get('/api/eupt/img/{file_name}', response_class=HTMLResponse)
-async def get_img(file_name: str, request: Request):
+
+@app.get('/api/eupt/img/{file_name}')
+async def get_img(file_name: str):
     """
     Returns an image file.
 
     Args:
         - file_name: The name of the file w/o extension
     """
-    img_path = Path(f'assets/img/{file_name}.svg')
-    if exists(img_path):
-        with open(img_path, mode='r', encoding='utf-8') as img_file:
-            result = img_file.read()
-    else:
-        result = 'Requested file not available.'
-    return fix_css_path(result, request.base_url)
+    img_path = Path(f'assets/img/{file_name}.svg')   
+    if isfile(img_path):
+        return FileResponse(img_path)
+    logging.warning(f'Requested image {file_name} not available.')
 
 @app.get('/api/eupt/{manifest}/manifest.json')
 async def get_manifest(manifest: str, request: Request):