Help: Drop incorrect advice from cmake-developer.7 manual

Drop the comment on the purpose of PATH_SUFFIXES in our Find Module
example.  It was incorrect.

Help/manual/cmake-developer.7.rst

@@ -867,7 +867,6 @@ look.
   find_path(Foo_INCLUDE_DIR
     NAMES foo.h
     PATHS ${PC_Foo_INCLUDE_DIRS}
-    # if you need to put #include <Foo/foo.h> in your code, add:
     PATH_SUFFIXES Foo
   )
   find_library(Foo_LIBRARY