fix coverity 11915 - dead code - introduced with fix for ticket 346

just get rid of unused variable was_present_null
reviewed by: nhosoi (Thanks!)

ldap/servers/slapd/attr.c

@@ -822,7 +822,6 @@ attr_add_valuearray(Slapi_Attr *a, Slapi_Value **vals, const char *dn)
     int i = 0;
     int numofvals = 0;
     int duplicate_index = -1;
-    int was_present_null = 0;
     int rc = LDAP_SUCCESS;
 
     if (valuearray_isempty(vals)) {
@@ -883,7 +882,7 @@ attr_add_valuearray(Slapi_Attr *a, Slapi_Value **vals, const char *dn)
                 duplicate_string,
                 a->a_type,
                 dn ? dn : "<null>", 
-                (was_present_null ? "duplicate new value" : "value exists"));
+                "value exists");
     }
     return( rc );
 }