BuildRequires: s/postgresql-devel/libpq-devel/

That's because we moved libpq.so.5 into libpq package, per
devel list discussion:
https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/U3XR5EGU2TPI2CDHBRBUD4M4LK5OHKU3/

Related: rhbz#1618698, rhbz#1623764

bacula.spec

@@ -61,7 +61,7 @@ BuildRequires:      libcap-devel
 BuildRequires:      lzo-devel
 BuildRequires:      ncurses-devel
 BuildRequires:      openssl-devel
-BuildRequires:      postgresql-devel
+BuildRequires:      libpq-devel
 BuildRequires:      readline-devel
 BuildRequires:      sqlite-devel
 BuildRequires:      zlib-devel