Remove SMACK rule file(.rule) according three domain model

Remove SMACK rule file(.rule) according three domain model

Since SMACK only allows three labels, "_"(floor), "User", "System"
The labels of current rule file are not appropriate

Solution:
- Remove rule file (org.tizen.email.rule)
- Remove install statement about installing rule file described in CMakeLists.txt
- Remove file path and name declaration of spec file (packaging/org.tizen.email.spec)

Reference site
https://wiki.tizen.org/wiki/Security:SmackThreeDomainModel

Change-Id: I6505c15ff539ce7780a124c2d735bbe3e8b6fe29
Signed-off-by: seong.chung <seong.chung@samsung.com>