patch 8.2.4710: smart indenting does not work after completion

Problem:    Smart indenting does not work after completion.
Solution:   Set "can_si". (Christian Brabandt, closes #10113, closes #558)
diff --git a/src/edit.c b/src/edit.c
index 53e86ff..f30edd5 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -1293,6 +1293,9 @@
 	    disable_fold_update--;
 #endif
 	    compl_busy = FALSE;
+#ifdef FEAT_SMARTINDENT
+	    can_si = TRUE; // allow smartindenting
+#endif
 	    break;
 
 	case Ctrl_Y:	// copy from previous line or scroll down