Remove check option to show units in text label

Currently the feature to show temperature units while adding dive is
provided through checkbox in preferences->units section. This patch
disables this checkbox and always enables this feature.

Signed-off-by: Lakshman Anumolu <acrlakshman@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix divelogs.de upload error

The order of arguments to fread was incorrect.
In case of arguments "streamsize, 1" the returning value is 1, and
hence due to membuf[streamsize] = 0; line, membuf ends up being one
character long.
Fixed it by exchanging arguments to "1, streamsize". This way,
streamsize has the correct value.

Fixes #483

Signed-off-by: Venkatesh Shukla <venkatesh.shukla.eee11@iitbhu.ac.in>
Acked-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>