Fix the bounds checking for area_get.

Fixes mouse at far left (x=0) not being able to click an area that starts at 0. Also fixes unclickable pixel between two adjacent areas

example
panel string
```
%{l}%{A:desktop 1:} 1 %{A}%{A:desktop 2:} 2 %{A}%{A:desktop 3:} 3 %{A}
```
panel output
```
 1  2  3 
```
example coordinates for area.begin-area.end would be
0-18 18-36 36-54

If you click at x=18 then neither 1 nor 2 would be clicked with old logic.