lib/srdb1 - set default datetime value to 2000-01-01

- 1900 is before the start of epoch and can result in unexpected
  behaviour with some time related functions

lib/srdb1/schema/entities.xml

@@ -28,6 +28,6 @@
 <!ENTITY DEFAULT_Q  "1.0">
 <!ENTITY DEFAULT_CALLID "Default-Call-ID">
 <!ENTITY DEFAULT_CSEQ "1">
-<!ENTITY DEFAULT_DATETIME "1900-01-01 00:00:01"> <!-- postgresql doesn't like 0000-00-00 00:00:00 -->
+<!ENTITY DEFAULT_DATETIME "2000-01-01 00:00:01"> <!-- postgresql doesn't like 0000-00-00 00:00:00 -->
 <!ENTITY DEFAULT_FLAGS "0">
 <!ENTITY KAMAILIO_MOD_DOC "http://www.kamailio.org/docs/modules/devel/">