Update app.py

Fix the file extension issue

app.py

@@ -43,9 +43,7 @@ def run_cppcheck(source_code: str):
     # Check for the code checker tool
     ensure_tool("cppcheck")
 
-    print(source_code)
-
-    ext = ".c" if source_code.strip().startswith("#include") and ".c" in source_code_name else ".cpp"
+    ext = ".c" if source_code.endswith(".c") else ".cpp"
     tf = NamedTemporaryFile(suffix=ext, delete=False)
     print("ext" + ext)
 
@@ -83,6 +81,7 @@ def build_prompt(filename: str, issues: list):
         src = f.read()
     if not issues:
         return None
+
     summary = "\n".join([
         f"- {item['message']} at line {item['line']}"
         for item in issues