asterisk/AMI_Functions: Add workaround for empty 'Hint: ' field

It sometimes shows up empty, let's skip it to avoid breaking the decoder
for now, similar to what we do with other fields.

Change-Id: I50fb51fab3755e4d63f3a0bc06d90b42814231d2
diff --git a/asterisk/AMI_Functions.ttcn b/asterisk/AMI_Functions.ttcn
index 1f3dc5e..c05403e 100644
--- a/asterisk/AMI_Functions.ttcn
+++ b/asterisk/AMI_Functions.ttcn
@@ -261,6 +261,7 @@
 	patched_txt := f_str_replace(patched_txt, "DestExten: \r\n", "");
 	patched_txt := f_str_replace(patched_txt, "Exten: \r\n", "");
 	patched_txt := f_str_replace(patched_txt, "Extension: \r\n", "");
+	patched_txt := f_str_replace(patched_txt, "Hint: \r\n", "");
 
 	/* "AppData" field sometimes has a value containing separator ": ", which makes
 	 * TEXT dec not happy. Workaround it for now by removing the whole field line: