FILE PHOTO: The logo of free messaging app Line is pictured on a smartphone in this photo illustration taken in Tokyo, Japan September 23, 2014. REUTERS/Toru Hanai TOKYO (Reuters) - A survey of Line Corp's 3938.T chat app users in Tokyo and neighboring prefectures in partnership with Japan's health ministry found 7.1% of respondents in the capital reporting at least one of the symptoms of the coro