You can be more concise, and simply do
if (signal1)
servo1.write(70);
else
servo1.write(defPos); //defPos is set at 40 degrees
(I am assuming it was a typo and there is only one servo object.)
There's no need to compare to HIGH as HIGH reads as true and LOW as false.
Also for single line statements the braces are optional - however if one arm of
the if is complicated its best to use braces on both so they visually match - easier
to see the structure then.
There is yet another way to do this, using a conditional expression:
servo1.write (signal1 ? 70 : defPos) ;