New time proposed is automatic and matches current time and date

[cpgray]

This just started happening recently. I don't know what has changed. Using: Thunderbird 52.3.0 (64-bit) On Lubuntu LTS (Ubuntu 16.04.3 LTS) Lightning 5.4 Exchange EWS Provider 4.0.1002

When responding to invites with just an 'accept' and 'send response now', it proposes to change the meeting time to the current time (so proposed date and time matches date and time that message is sent).

For example,

Date: 2017-10-05 01:48 PM

Event Invitation Title: | New Time Proposed: ----------------- When: | Thu 5 Oct 2017 01:48 PM

[leonadler]

#610