patch 8.2.0955: build fails

Problem:    Build fails.
Solution:   Add missing struct change.
diff --git a/src/structs.h b/src/structs.h
index cdadb83..700ac54 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -2423,6 +2423,7 @@
     regprog_T	*b_cap_prog;	    // program for 'spellcapcheck'
     char_u	*b_p_spf;	    // 'spellfile'
     char_u	*b_p_spl;	    // 'spelllang'
+    char_u	*b_p_spo;	    // 'spelloptions'
     int		b_cjk;		    // all CJK letters as OK
 #endif
 #if !defined(FEAT_SYN_HL) && !defined(FEAT_SPELL)