Get rid of dee-devel, gtk3-devel in Fedora specfile (#151)

These dependencies were not used after removing GTK code in #129.

kepka.spec

@@ -36,9 +36,7 @@ BuildRequires: range-v3-devel
 BuildRequires: openssl-devel
 BuildRequires: minizip-devel
 BuildRequires: opus-devel
-BuildRequires: gtk3-devel
 BuildRequires: zlib-devel
-BuildRequires: dee-devel
 BuildRequires: xz-devel
 
 # Development packages for libtgvoip...