Correct erroneous assumption about port being the last line of the pid file

[rtibbles]

Currently the code to get the active port from the Kolibri PID file assumes that it can keep reading the file until the file finishes:

kolibri-installer-windows/src/gui-source/Kolibri/Kolibri.cpp

Line 76 in a55fb87

while (getline(file, line)) {

However, recent updates have added additional lines to this PID file, meaning that it is now reading the wrong information.

Instead, we should update the code to only read the second line of the PID file to get the port.

Ideally, in future, we would use Kolibri's utils to determine this information, rather than introspecting the pid file - this will make it less brittle to future changes. But this fix will do for now.

[micahscopes]

Here's a gist verifying that the method of calling getline twice does indeed get the second line in a predictable way:

https://gist.github.com/micahscopes/348cdbed199588cdbf5a281291cc8b6a

I'm not sure what's going wrong at this point.

c.c. @jonboiser @rtibbles

[rtibbles]

Fixed in #188 and #192