patch 8.2.4693: new regexp does not accept pattern "\%>0v"

Problem:    new regexp does not accept pattern "\%>0v".
Solution:   Do accept digit zero.
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index d658a6b..2c79a49 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -1640,6 +1640,7 @@
 			long_u	n = 0;
 			int	cmp = c;
 			int	cur = FALSE;
+			int	got_digit = FALSE;
 
 			if (c == '<' || c == '>')
 			    c = getchr();
@@ -1668,12 +1669,13 @@
 			    }
 			    n = tmp;
 			    c = getchr();
+			    got_digit = TRUE;
 			}
 			if (c == 'l' || c == 'c' || c == 'v')
 			{
 			    long_u limit = INT_MAX;
 
-			    if (!cur && n == 0)
+			    if (!cur && !got_digit)
 			    {
 				semsg(_(e_nfa_regexp_missing_value_in_chr),
 								  no_Magic(c));