don't mention bzr in "make distclean" warning message

sql/CMakeLists.txt

@@ -304,9 +304,7 @@ ADD_CUSTOM_TARGET(dist
 
 ADD_CUSTOM_TARGET(distclean
   COMMAND ${CMAKE_COMMAND} -E echo  WARNING: distclean target is not functional
-  COMMAND ${CMAKE_COMMAND} -E echo  Use 'bzr clean-tree' with --unknown and/or
-    --ignored parameter instead
-  COMMAND ${CMAKE_COMMAND} -E echo  For git repositories, use 'git clean -Xdf'
+  COMMAND ${CMAKE_COMMAND} -E echo  Use 'git clean -Xdf' instead
   VERBATIM
   )