Remove unnecessary dependency on openmotif

Requirement was an artifact of older version of mesa, and is no longer necessary.

contrib/packages/rpm/el5/SPECS/tigervnc.spec

@@ -120,8 +120,6 @@ BuildRequires: git, gperf, intltool, libtalloc-devel
 BuildRequires: kernel-headers, libatomic_ops-devel
 BuildRequires: xz
 
-BuildRequires: openmotif-devel
-Requires: openmotif, openmotif22
 Requires(post): initscripts chkconfig coreutils
 Requires(postun):coreutils
 Requires: hicolor-icon-theme

contrib/packages/rpm/el6/SPECS/tigervnc.spec

@@ -36,8 +36,6 @@ BuildRequires: cmake28
 BuildRequires: xorg-x11-server-devel
 %endif
 
-BuildRequires: openmotif-devel
-Requires: openmotif, openmotif22
 Requires(post): initscripts chkconfig coreutils
 Requires(postun): coreutils
 Requires: libjpeg-turbo