docs: remove leading spaces on error handling example (#1032)

Author: thinkingserious

use_cases/error_handling.md

@@ -6,24 +6,24 @@ Please see [here](https://github.com/sendgrid/python-http-client/blob/HEAD/pytho
 There are also email specific exceptions located [here](../sendgrid/helpers/mail/exceptions.py)
 
 ```python
-  import os
-  from sendgrid import SendGridAPIClient
-  from sendgrid.helpers.mail import (From, To, Subject, PlainTextContent, HtmlContent, Mail)
-  from python_http_client import exceptions
+import os
+from sendgrid import SendGridAPIClient
+from sendgrid.helpers.mail import (From, To, Subject, PlainTextContent, HtmlContent, Mail)
+from python_http_client import exceptions
 
-  sendgrid_client = SendGridAPIClient(os.environ.get('SENDGRID_API_KEY'))
-  from_email = From("help@twilio.com")
-  to_email = To("ethomas@twilio.com")
-  subject = Subject("Sending with Twilio SendGrid is Fun")
-  plain_text_content = PlainTextContent("and easy to do anywhere, even with Python")
-  html_content = HtmlContent("<strong>and easy to do anywhere, even with Python</strong>")
-  message = Mail(from_email, to_email, subject, plain_text_content, html_content)
-  try:
-      response = sendgrid_client.send(message)
-      print(response.status_code)
-      print(response.body)
-      print(response.headers)
-  except exceptions.BadRequestsError as e:
-      print(e.body)
-      exit()
+sendgrid_client = SendGridAPIClient(os.environ.get('SENDGRID_API_KEY'))
+from_email = From("help@twilio.com")
+to_email = To("ethomas@twilio.com")
+subject = Subject("Sending with Twilio SendGrid is Fun")
+plain_text_content = PlainTextContent("and easy to do anywhere, even with Python")
+html_content = HtmlContent("<strong>and easy to do anywhere, even with Python</strong>")
+message = Mail(from_email, to_email, subject, plain_text_content, html_content)
+try:
+    response = sendgrid_client.send(message)
+    print(response.status_code)
+    print(response.body)
+    print(response.headers)
+except exceptions.BadRequestsError as e:
+    print(e.body)
+    exit()
 ```