gnulib-tool.py: Remove some unused variable assignments. * pygnulib/GLEmiter.py (GLEmiter.autoconfSnippets): Remove unused variable. * pygnulib/GLInfo.py (GLInfo.date, GLInfo.version): Remove assignments to variables unconditionally set in try, except blocks. * pygnulib/GLModuleSystem.py (GLModule.getConditionalName) (GLModule.getShellFunc, GLModule.getShellVar): Likewise.