Add cacert.pem file to pear package.

Fixes #3591

build.xml

@@ -151,6 +151,7 @@
 			</release>
 			<exceptions key="Cake/VERSION.txt">php</exceptions>
 			<exceptions key="Cake/LICENSE.txt">php</exceptions>
+			<exceptions key="Cake/Config/cacert.pem">php</exceptions>
 		</d51pearpkg2>
 	</target>