Don't copy INSTALL documentation to system docs

The INSTALL documentation is not relevant after installation, especially
if packages are used.

This does prevent a rpmlint warning.

refs #5818

CMakeLists.txt

@@ -127,7 +127,7 @@ endif()
 configure_file(config.h.cmake ${CMAKE_CURRENT_BINARY_DIR}/config.h ESCAPE_QUOTES)
 
 install(
-  FILES README COPYING COPYING.Exceptions AUTHORS ChangeLog INSTALL NEWS
+  FILES README COPYING COPYING.Exceptions AUTHORS ChangeLog NEWS
   DESTINATION ${CMAKE_INSTALL_DOCDIR}
 )