Fix regex on ASA password prompt (#49438)

On Cisco ASAv on AWS, the prompt is 'Password', thus the privilege
elevation fails, we need to check upper and lower p.

lib/ansible/plugins/terminal/asa.py

@@ -58,7 +58,7 @@ class TerminalModule(TerminalBase):
         if passwd:
             # Note: python-3.5 cannot combine u"" and r"" together.  Thus make
             # an r string and use to_text to ensure it's text on both py2 and py3.
-            cmd[u'prompt'] = to_text(r"[\r\n]?password: $", errors='surrogate_or_strict')
+            cmd[u'prompt'] = to_text(r"[\r\n]?[Pp]assword: $", errors='surrogate_or_strict')
             cmd[u'answer'] = passwd
 
         try: