Use a consistent %bcond syntax

Cython.spec

@@ -1,8 +1,8 @@
-%bcond_without tests
+%bcond tests 1
 
 # This bcond allows to ship a non-compiled version
 # Slower, but sometimes necessary with alpha Python versions
-%bcond_without cython_compile
+%bcond cython_compile 1
 
 # We don't ship emacs-cython-mode in EL.
 %bcond emacs %{undefined rhel}