Escape multi-line quotes properly

Fix Rapptz#5897

Author: Rapptz

discord/utils.py

@@ -482,7 +482,7 @@ def resolve_template(code):
 
 _MARKDOWN_ESCAPE_COMMON = r'^>(?:>>)?\s|\[.+\]\(.+\)'
 
-_MARKDOWN_ESCAPE_REGEX = re.compile(r'(?P<markdown>%s|%s)' % (_MARKDOWN_ESCAPE_SUBREGEX, _MARKDOWN_ESCAPE_COMMON))
+_MARKDOWN_ESCAPE_REGEX = re.compile(r'(?P<markdown>%s|%s)' % (_MARKDOWN_ESCAPE_SUBREGEX, _MARKDOWN_ESCAPE_COMMON), re.MULTILINE)
 
 def escape_markdown(text, *, as_needed=False, ignore_links=True):
     r"""A helper function that escapes Discord's markdown.
@@ -521,7 +521,7 @@ def replacement(match):
         regex = r'(?P<markdown>[_\\~|\*`]|%s)' % _MARKDOWN_ESCAPE_COMMON
         if ignore_links:
             regex = '(?:%s|%s)' % (url_regex, regex)
-        return re.sub(regex, replacement, text)
+        return re.sub(regex, replacement, text, 0, re.MULTILINE)
     else:
         text = re.sub(r'\\', r'\\\\', text)
         return _MARKDOWN_ESCAPE_REGEX.sub(r'\\\1', text)