patch 8.1.1463: gcc warns for uninitialized variable

Problem:    Gcc warns for uninitialized variable.
Solution:   Put usage inside "if".  (Ken Takata)

src/textprop.c

@@ -1240,9 +1240,12 @@ join_prop_lines(
     if (line == NULL)
 	return;
     mch_memmove(line, newp, len);
+    if (oldproplen > 0)
+    {
 	l = oldproplen * sizeof(textprop_T);
 	mch_memmove(line + len, props, l);
 	len += l;
+    }
 
     for (i = 0; i < count - 1; ++i)
 	if (prop_lines[i] != NULL)

src/version.c

@@ -767,6 +767,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1463,
 /**/
     1462,
 /**/