tradfri: Improve color temp support detection (#7211)

virtualization/Docker/Dockerfile.dev

@@ -12,6 +12,7 @@ MAINTAINER Paulus Schoutsen <Paulus@PaulusSchoutsen.nl>
 #ENV INSTALL_OPENZWAVE no
 #ENV INSTALL_LIBCEC no
 #ENV INSTALL_PHANTOMJS no
+#ENV INSTALL_COAP_CLIENT no
 
 VOLUME /config
 
@@ -25,7 +26,7 @@ RUN virtualization/Docker/setup_docker_prereqs
 # Install hass component dependencies
 COPY requirements_all.txt requirements_all.txt
 RUN pip3 install --no-cache-dir -r requirements_all.txt && \
-    pip3 install --no-cache-dir mysqlclient psycopg2 uvloop
+    pip3 install --no-cache-dir mysqlclient psycopg2 uvloop cchardet
 
 # BEGIN: Development additions