patch 8.0.0533: abbreviation doesn't work after backspacing newline

Problem:    Abbreviation doesn't work after backspacing newline. (Hkonrk)
Solution:   Set the insert start column. (closes #1609)
diff --git a/src/edit.c b/src/edit.c
index 8aa15af..fae48c6 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -9017,7 +9017,7 @@
 #endif
 
     /*
-     * delete newline!
+     * Delete newline!
      */
     if (curwin->w_cursor.col == 0)
     {
@@ -9032,7 +9032,7 @@
 			       (linenr_T)(curwin->w_cursor.lnum + 1)) == FAIL)
 		return FALSE;
 	    --Insstart.lnum;
-	    Insstart.col = MAXCOL;
+	    Insstart.col = STRLEN(ml_get(Insstart.lnum));
 	}
 	/*
 	 * In replace mode: