Use INSTALLFOLDER in Windows drawpile:// handling

Instead of INSTALLDIR, because that doesn't exist. This should make the
URL registration for drawpile:// URLs actually work in Windows, which it
didn't before due to missing the path to the executable.

ChangeLog

@@ -38,6 +38,7 @@ Unreleased Version 2.2.0-pre
  * Feature: Allow increasing and decreasing key frame exposure. Thanks Tabuley for suggesting.
  * Fix: Properly update the view when the canvas size changes, rather than leaving stale areas outside of the canvas.
  * Feature: Add shortcuts to swap the contents of brush slots to allow for a kind of toggling behavior using a single shortcut. Thanks xxxx for suggesting.
+ * Fix: Make drawpile:// URL handling actually work on Windows. Thanks Sal for reporting.
 
 2023-07-31 Version 2.2.0-beta.6
  * Fix: Don't forget account password when entering a wrong session password.

cmake/DrawpileFileExtensions.cmake

@@ -462,10 +462,10 @@ function(_wxs_generate_urls out_var exe)
 					"\t\t\t<RegistryValue Name=\"URL Protocol\" Value=\"\" Type=\"string\"/>\n"
 					"\t\t\t<RegistryValue Value=\"URL: ${NAME}\" Type=\"string\"/>\n"
 					"\t\t\t<RegistryKey Key=\"DefaultIcon\">\n"
-					"\t\t\t\t<RegistryValue Value=\"[INSTALLDIR]${exe}\" Type=\"string\"/>\n"
+					"\t\t\t\t<RegistryValue Value=\"[INSTALLFOLDER]${exe}\" Type=\"string\"/>\n"
 					"\t\t\t</RegistryKey>\n"
 					"\t\t\t<RegistryKey Key=\"shell\\open\\command\">\n"
-					"\t\t\t\t<RegistryValue Value=\"&quot\;[INSTALLDIR]${exe}&quot\; &quot\;%1&quot\;\" Type=\"string\"/>\n"
+					"\t\t\t\t<RegistryValue Value=\"&quot\;[INSTALLFOLDER]${exe}&quot\; &quot\;%1&quot\;\" Type=\"string\"/>\n"
 					"\t\t\t</RegistryKey>\n"
 					"\t\t</RegistryKey>\n"
 				)