patch 8.1.0549: netbeans test depends on README.txt contents

Problem:    Netbeans test depends on README.txt contents.
Solution:   Use a generated file instead.

src/version.c

@@ -792,6 +792,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    549,
 /**/
     548,
 /**/