Fix ecbuild_disable_unused_feature

Author: iainrussell

cmake/ecbuild_features.cmake

@@ -59,7 +59,7 @@ endfunction()
 # Disable the feature ${_name} globally (if it has not been enabled in any subproject)
 function( ecbuild_disable_unused_feature _name )
   get_property( _enabled GLOBAL PROPERTY ENABLED_FEATURES )
-  if ( NOT _name IN_LIST _enabled ) # if not already disabled
+  if ( _name IN_LIST _enabled ) # if not already disabled
     ecbuild_disable_feature( ${_name} )
   endif()
-endfunction()
+endfunction()