patch 8.1.0803: session file has problem with single quote in file name

Problem:    Session file has problem with single quote in file name. (Jon
            Crowe)
Solution:   Use a double quoted string.  Add a test.

src/version.c

@@ -791,6 +791,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    803,
 /**/
     802,
 /**/