Small code consistency improvement

Adjust the way the increment operators are placed to be consistent
throughout the function.  Fixup for commit commit c1da728106.

src/bin/pg_dump/connectdb.c

@@ -142,7 +142,8 @@ ConnectDatabase(const char *dbname, const char *connection_string,
 		if (override_dbname)
 		{
 			keywords[i] = "dbname";
-			values[i++] = override_dbname;
+			values[i] = override_dbname;
+			i++;
 		}
 
 		keywords[i] = "fallback_application_name";