patch 7.4.1865

Problem:    Memory leaks in tet49. (Dominique Pelle)
Solution:   Use NULL instead of an empty string.

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1865,
 /**/
     1864,
 /**/