correcting white spacing

Author: mckenziewest

src/sage/rings/polynomial/multi_polynomial_libsingular.pyx

@@ -2403,13 +2403,11 @@ cdef class MPolynomial_libsingular(MPolynomial):
             ...
             ZeroDivisionError: rational division by zero
 
-        Ensure that :trac:`17638` is fixed
+        Ensure that :trac:`17638` is fixed::
 
-        ::
-
-            sage: R.<x,y> = PolynomialRing(QQ,order="neglex")
-            sage: f = 1+y
-            sage: g = 1+x
+            sage: R.<x,y> = PolynomialRing(QQ, order="neglex")
+            sage: f = 1 + y
+            sage: g = 1 + x
             sage: h = f/g
             sage: h*g == f
             True