Help: Remove recommendation about checking minimum CMake version.

If this file is being executed, the user has the CMake version
providing it.

Help/manual/cmake-developer.7.rst

@@ -943,16 +943,6 @@ licence notice block
   # (To distribute this file outside of CMake, substitute the full
   #  License text for the above reference.)
 
-If the module is new to CMake, you may want to provide a warning for
-projects that do not require a high enough CMake version.
-
-.. code-block:: cmake
-
-  if(CMAKE_MINIMUM_REQUIRED_VERSION VERSION_LESS 3.0.0)
-    message(AUTHOR_WARNING
-      "Your project should require at least CMake 3.0.0 to use FindFoo.cmake")
-  endif()
-
 Now the actual libraries and so on have to be found.  The code here will
 obviously vary from module to module (dealing with that, after all, is the
 point of find modules), but there tends to be a common pattern for libraries.