video: Fix render failure for 1x1 size

video: Fix render failure for 1x1 size

While determining whether the given vertices represent the portrait or
the landscape rectangle, the margin of 1 pixel has been used because
sometimes there has been 1 pixel difference between two adjacent
vertices. This could be because of evas map algorithm, but I'm not sure.

If the dimension of rectangle would be 1x1 it wouldn't be worked, so if
the given vertices represent the rectangle that has 1x1 dimension, then
no margin would be used.

Change-Id: I0c776060ed3124dfd72717e474f193929ae51c6a