egypt.xml:change sphinx to scarab

I figured no one would mind if I got rid of the sphinx. These starting
units, such as the Persian snakepit, and tech defense tower sometimes
get in people's way, and often positioned in useless ways.

If anybody wants to discuss it further, let me know.

techs/zetapack/factions/egypt/egypt.xml

@@ -9,7 +9,7 @@
 	</starting-resources>
 	<starting-units>
 		<unit name="pyramid" amount="1"/>
-		<unit name="sphinx" amount="1"/>
+		<unit name="scarab" amount="1"/>
 		<unit name="slave" amount="3"/>
 		<unit name="spearman" amount="1"/>
 		<unit name="spearthrower" amount="1"/>