Only install redist if it exists

CMakeLists.txt

@@ -356,7 +356,6 @@ if(WIN32)
     INSTALL(FILES ${files} DESTINATION ".")
     INSTALL(FILES "${OpenMW_BINARY_DIR}/openmw.cfg.install" DESTINATION "." RENAME "openmw.cfg")
     INSTALL(FILES "${OpenMW_BINARY_DIR}/launcher.cfg" "${OpenMW_BINARY_DIR}/launcher.qss" DESTINATION ".")
-    INSTALL(FILES "${OpenMW_BINARY_DIR}/vcredist_x86.exe" DESTINATION "redist")
     INSTALL(DIRECTORY "${OpenMW_BINARY_DIR}/resources" DESTINATION ".")
 
     SET(CPACK_GENERATOR "NSIS")
@@ -370,12 +369,16 @@ if(WIN32)
     SET(CPACK_PACKAGE_DESCRIPTION_FILE "${OpenMW_SOURCE_DIR}/readme.txt")
     SET(CPACK_RESOURCE_FILE_LICENSE "${OpenMW_SOURCE_DIR}/GPL3.txt")
     SET(CPACK_NSIS_EXECUTABLES_DIRECTORY ".")
-    SET(CPACK_NSIS_EXTRA_INSTALL_COMMANDS "ExecWait '\\\"$INSTDIR\\\\redist\\\\vcredist_x86.exe\\\" /q'" )
     SET(CPACK_NSIS_DISPLAY_NAME "OpenMW")
     SET(CPACK_NSIS_HELP_LINK "http:\\\\\\\\www.openmw.org")
     SET(CPACK_NSIS_URL_INFO_ABOUT "http:\\\\\\\\www.openmw.org")
     SET(CPACK_NSIS_INSTALLED_ICON_NAME "omwlauncher.exe")
 
+    if(EXISTS "${OpenMW_BINARY_DIR}/vcredist_x86.exe")
+        INSTALL(FILES "${OpenMW_BINARY_DIR}/vcredist_x86.exe" DESTINATION "redist")
+        SET(CPACK_NSIS_EXTRA_INSTALL_COMMANDS "ExecWait '\\\"$INSTDIR\\\\redist\\\\vcredist_x86.exe\\\" /q'" )
+    endif(EXISTS "${OpenMW_BINARY_DIR}/vcredist_x86.exe")
+
     include(CPack)
 endif(WIN32)