testsuite: fix icontheme test failure on win32 [v2]
g_str_has_suffix()
fails on win32/msys2 due to different path separators (filename
uses /
, path
uses \
).
Compare URIs instead.
Typical symptom on win32:
(C:/TEMP/libs/gtk/_build/testsuite/gtk/icontheme.exe:12384): ERROR **: Icon for "simple" with flags 0 at size 16 should be ".../icons/16x16/simple.png" but is "...C:\TEMP\libs\gtk\testsuite\gtk\icons\16x16\simple.png"