DOC: fixed release version in RNs

Author: Liudmila Mantrova

doc/src/sgml/release-proee-10.sgml

@@ -7,7 +7,7 @@
   </formalpara>
   <sect2>
     <title>Overview</title>
-    <para>This release is based on <productname>Postgres Pro Standard</productname> 10.2.1
+    <para>This release is based on <productname>Postgres Pro Standard</productname> 10.3.1
       and <productname>Postgres Pro Enterprise</productname> 10.2.1.
       As compared with <productname>Postgres Pro Enterprise</productname> 10.2.1,
       this version provides the following changes:</para>