db schema: added missing column in dispatcher table

- version set to 4

lib/srdb1/schema/dispatcher.xml

@@ -9,7 +9,7 @@
 
 <table id="dispatcher" xmlns:db="http://docbook.org/ns/docbook">
     <name>dispatcher</name>
-    <version>3</version>
+    <version>4</version>
     <type db="mysql">&MYSQL_TABLE_TYPE;</type>
     <description>
         <db:para>This table is used by the dispatcher module. It contains the sets of destinations used for load balancing and dispatching. More information about the dispatcher module can be found at: &KAMAILIO_MOD_DOC;dispatcher.html
@@ -58,6 +58,14 @@
         <natural/>
     </column>
 
+    <column>
+        <name>attrs</name>
+        <type>string</type>
+        <size>128</size>
+        <default/>
+        <description>Attributes specific for this destination</description>
+    </column>
+
     <column>
         <name>description</name>
         <type>string</type>