Don't add icon to Windows build

For some reason adding an icon causes the EXE to be flagged by Nexus as
suspicious even though it passes the VirusTotal test

build-win.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
 # Use MINGW for cross-compilation
-x86_64-w64-mingw32-g++ main.cpp modlimitfix.res -o modlimitfix.exe -std=c++17
+x86_64-w64-mingw32-g++ main.cpp -o modlimitfix.exe -std=c++17