Removed Windows branch, made Windows exe file windowed.

README.md

@@ -12,9 +12,7 @@ A 32-bit stand-alone Windows binary with the script is provided in [the
 release notes](https://git.scc.kit.edu/KIT-CA/RecodeCertificate/tags).  To
 use the Windows binary, simply double-click the executable file.
 
-If you want to roll the Windows EXE file yourself, check out the [Windows
-branch](https://git.scc.kit.edu/KIT-CA/RecodeCertificate/tree/Windows).  A
-Windows system with a working Python 3 installation and the `pyinstaller`
-package is required.  After checking out the Windows branch, run
-`Windows\roll_executable.bat`.  The resulting binary will be located in
-`dist\RecodeCertificate.exe`.
+If you want to roll the Windows EXE file yourself, you will need a Windows
+system with a working Python 3 installation and the `pyinstaller` and the
+`pyopenssl` packages installed.  Running `Windows\roll_executable.bat` should
+create a working binary in `dist\RecodeCertificate.exe`.

Windows/roll_executable.bat

-pyinstaller --onefile --icon Windows\RecodeCertificate.ico RecodeCertificate.py
+pyinstaller --windowed --onefile --icon Windows\RecodeCertificate.ico RecodeCertificate.py