stdin2discord: add verbose logging on query failure. fix logic for long messages

stdin2discord.py

@@ -11,12 +11,17 @@ def send(_msg: str):
                       data=f'content=```diff\n{requests.utils.quote(_msg)}```'.encode('utf-8'),
                       headers = {'Content-Type': 'application/x-www-form-urlencoded'}
                      )
-    r.raise_for_status()
+    try:
+        r.raise_for_status()
+
+    except Exception:
+        print(r.text)
+        raise
 
 msg = ''
 
 for line in sys.stdin:
-    if len(msg + line) >= 2000:
+    if len(msg + line) >= 1900:
         send(msg)
         msg = ''