Disable support for missing codecs in RHEL

soxr-devel and lame-devel are not available in certain versions of RHEL.
Let's conditionaly disable support for them. Just note that this will just
reduce the number of available codecs for sound redirection.

freerdp.spec

@@ -14,6 +14,12 @@
 # https://bugzilla.redhat.com/show_bug.cgi?id=1639165
 %{!?rhel:%global _with_server 1}
 
+# Disable support for missing codecs in RHEL
+%{!?rhel:%global _with_soxr 1}
+%if 0%{?fedora} || 0%{?rhel} >= 8
+%global _with_lame 1
+%endif
+
 Name:           freerdp
 Version:        2.1.1
 Release:        1%{?dist}
@@ -30,7 +36,7 @@ BuildRequires:  alsa-lib-devel
 BuildRequires:  cmake >= 2.8
 BuildRequires:  cups-devel
 BuildRequires:  gsm-devel
-BuildRequires:  lame-devel
+%{?_with_lame:BuildRequires:  lame-devel}
 BuildRequires:  libicu-devel
 BuildRequires:  libjpeg-turbo-devel
 BuildRequires:  libX11-devel
@@ -67,7 +73,7 @@ BuildRequires:  pkgconfig(libpulse)
 BuildRequires:  pkgconfig(libsystemd)
 BuildRequires:  pkgconfig(libusb-1.0)
 BuildRequires:  pkgconfig(openssl)
-BuildRequires:  pkgconfig(soxr)
+%{?_with_soxr:BuildRequires:  pkgconfig(soxr)}
 BuildRequires:  pkgconfig(wayland-client)
 BuildRequires:  pkgconfig(wayland-scanner)
 BuildRequires:  pkgconfig(xkbcommon)
@@ -165,7 +171,7 @@ find . -name "*.c" -exec chmod 664 {} \;
     -DWITH_ICU=ON \
     -DWITH_IPP=OFF \
     -DWITH_JPEG=ON \
-    -DWITH_LAME=ON \
+    -DWITH_LAME=%{?_with_lame:ON}%{?!_with_lame:OFF} \
     -DWITH_MANPAGES=ON \
     -DWITH_OPENH264=%{?_with_openh264:ON}%{?!_with_openh264:OFF} \
     -DWITH_OPENSSL=ON \
@@ -175,7 +181,7 @@ find . -name "*.c" -exec chmod 664 {} \;
     -DWITH_SERVER_INTERFACE=%{?_with_server:ON}%{?!_with_server:OFF} \
     -DWITH_SHADOW_X11=%{?_with_server:ON}%{?!_with_server:OFF} \
     -DWITH_SHADOW_MAC=%{?_with_server:ON}%{?!_with_server:OFF} \
-    -DWITH_SOXR=ON \
+    -DWITH_SOXR=%{?_with_soxr:ON}%{?!_with_soxr:OFF} \
     -DWITH_WAYLAND=ON \
     -DWITH_X11=ON \
     -DWITH_X264=%{?_with_x264:ON}%{?!_with_x264:OFF} \