patch 9.0.0916: getbufline() is inefficient for getting a single line

Problem:    getbufline() is inefficient for getting a single line.
Solution:   Add getbufoneline().
diff --git a/src/version.c b/src/version.c
index 136521d..8a71fd3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    916,
+/**/
     915,
 /**/
     914,