Update element_base.pyx

Author: GiacomoPope

src/sage/rings/finite_rings/element_base.pyx

@@ -143,7 +143,7 @@ cdef class FiniteRingElement(CommutativeRingElement):
             raise ValueError("unknown algorithm")
 
     def to_bytes(self, byteorder="big"):
-        """
+        r"""
         Return an array of bytes representing an integer.
 
         Internally relies on the python ``int.to_bytes()`` method.