Correct archive enum

Likely a typo, should fix support for Mozilla Thunderbird
https://community.grommunio.com/d/2362-thunderbird-ews

Author: amaccuish

exch/ews/enums.hpp

@@ -345,7 +345,7 @@ struct Enum {
 	STR(adminauditlogs);
 	STR(allcategorizeditems);
 	STR(alltaggeditems);
-	STR(archiv);
+	STR(archive);
 	STR(archivedeleteditems);
 	STR(archiveinbox);
 	STR(archivemsgfolderroot);