patch 8.0.0266: compiler warning for using uninitialized variable

Problem:    Compiler warning for using uninitialized variable.
Solution:   Set tab_number also when there is an error.

Author: brammool

src/ex_docmd.c

@@ -7533,7 +7533,10 @@ get_tabpage_arg(exarg_T *eap)
     else if (eap->addr_count > 0)
     {
 	if (unaccept_arg0 && eap->line2 == 0)
+	{
 	    eap->errmsg = e_invrange;
+	    tab_number = 0;
+	}
 	else
 	{
 	    tab_number = eap->line2;

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    266,
 /**/
     265,
 /**/