patch 8.2.1446: Vim9: line number in error message is not correct

Problem:    Vim9: line number in error message is not correct.
Solution:   Set SOURCING_LNUM before calling emsg(). (closes #6708)
diff --git a/src/version.c b/src/version.c
index 3ae2c72..a8a1d49 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1446,
+/**/
     1445,
 /**/
     1444,