[hotfix][workaround] so latest head breaks this docker image, so this…

… pins captagent at a version before fixing what's up with captagent head for QXIP#6

Dockerfile

@@ -6,7 +6,8 @@ ENV captagent_version 6.1
 RUN apt-get update -qq && apt-get install --no-install-recommends --no-install-suggests -yqq ca-certificates git make m4 automake autoconf libtool libcap-dev libexpat-dev libpcap-dev zlib1g-dev openssl libssl-dev bison flex  libjson0 libjson0-dev libcurl4-gnutls-dev libjson-c-dev && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /usr/src
-RUN git clone https://github.com/sipcapture/captagent.git captagent
+ENV captagent_sha1 cf757a2e0bb883146e0178d15ee3659c03d9fd6c
+RUN git clone --branch $captagent_version https://github.com/sipcapture/captagent.git captagent && cd captagent && git reset --hard $captagent_sha1
 
 WORKDIR /usr/src/captagent
 RUN ./build.sh