Update Dockerfile

lisrtp to 2.6.0

Author: wangsrGit119

Dockerfile

@@ -46,7 +46,7 @@ RUN cd /tmp/ &&  LIBWEBSOCKET="4.3.2" && wget https://github.com/warmcat/libwebs
     make && make install
 
 # libsrtp
-RUN cd /tmp/ && SRTP="2.2.0" && wget https://github.com/cisco/libsrtp/archive/v$SRTP.tar.gz && \
+RUN cd /tmp/ && SRTP="2.6.0" && wget https://github.com/cisco/libsrtp/archive/v$SRTP.tar.gz && \
     tar xfv v$SRTP.tar.gz && \
     cd libsrtp-$SRTP && \
     ./configure --prefix=/usr --enable-openssl && \