Mike Fleetwood authored Feb 18, 2019 and Curtis Gedak committed Mar 23, 2019

Now that GParted requires Gtk3 there is no need to use floating point
numbers for compatibility with Gtk <= 2.22.  Replace with symbolic
alignment constants.

Relevant commit history:

*   6efa6234
    Add optional yalign argument to Utils::mk_label() method

*   be2689ad
    Stop using deprecated widget alignment enumerators (#652044)