screen: retain the placewewant also when using an alternate speller

When using the default speller or the formatter, the placewewant is
remembered.  So it should be remembered too when the user specifies
a different speller.

(This behavior was inadvertently lost last year, in commit 82d737ee.)

src/text.c

@@ -2927,6 +2927,7 @@ const char *do_alt_speller(char *tempfile_name)
 {
     int alt_spell_status;
     size_t current_x_save = openfile->current_x;
+    size_t pww_save = openfile->placewewant;
     ssize_t current_y_save = openfile->current_y;
     ssize_t lineno_save = openfile->current->lineno;
     struct stat spellfileinfo;
@@ -3075,6 +3076,7 @@ const char *do_alt_speller(char *tempfile_name)
     /* Go back to the old position. */
     goto_line_posx(lineno_save, current_x_save);
     openfile->current_y = current_y_save;
+    openfile->placewewant = pww_save;
     edit_update(STATIONARY);
 
     /* Stat the temporary file again, and mark the buffer as modified only