patch 8.2.0507: getbufvar() may get the wrong dictionary

Problem:    Getbufvar() may get the wrong dictionary. (David le Blanc)
Solution:   Check for empty name. (closes #5878)

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    507,
 /**/
     506,
 /**/