Adds openssl-devel to the RPMs dependencies

pyOpenSSL (required by glanceclient) fails to build if openssl
header files are missing.

Change-Id: I3ebce749ee9ca88cbbecc6b7676a086d82670f4d
Fixes: bug #1188650
diff --git a/files/rpms/general b/files/rpms/general
index 764b602..2a1ee4b 100644
--- a/files/rpms/general
+++ b/files/rpms/general
@@ -6,6 +6,7 @@
 git-core
 openssh-server
 openssl
+openssl-devel # to rebuild pyOpenSSL if needed
 libxml2-devel # dist:rhel6 [2]
 libxslt-devel # dist:rhel6 [2]
 psmisc