fix doctest errors

due to changed printing

Author: saraedum

src/doc/en/reference/coercion/index.rst

@@ -222,11 +222,11 @@ be obtained and queried.
 
     sage: cm.explain(ZZ['x','y'], QQ['x'])
     Coercion on left operand via
-       Conversion map:
+       Coercion map:
          From: Multivariate Polynomial Ring in x, y over Integer Ring
          To:   Multivariate Polynomial Ring in x, y over Rational Field
     Coercion on right operand via
-       Conversion map:
+       Coercion map:
          From: Univariate Polynomial Ring in x over Rational Field
          To:   Multivariate Polynomial Ring in x, y over Rational Field
     Arithmetic performed after coercions.

src/doc/en/thematic_tutorials/coercion_and_categories.rst

@@ -824,7 +824,7 @@ thus have::
     sage: P1.has_coerce_map_from(P2)
     True
     sage: P1.coerce_map_from(P2)
-    Conversion map:
+    Coercion map:
       From: Multivariate Polynomial Ring in w, v over Integer Ring
       To:   Multivariate Polynomial Ring in v, w over Rational Field