Dockerfiles update according to the 7.2.1 release

Change-Id: I740e277d27cf46ff8def8dec16363d44c3f06f84
Signed-off-by: Adam Knapp <adam.knapp@sigmatechnology.se>

docker/Dockerfile.alpine

@@ -18,7 +18,7 @@ RUN echo 'sh' >> /home/titan/.bashrc
 WORKDIR /home/titan
 RUN git clone https://github.com/eclipse/titan.core.git
 WORKDIR /home/titan/titan.core/
-RUN git checkout tags/7.2.1
+RUN git checkout tags/7.2.1_final
 
 ## SET UP ENV VARIABLES
 ENV TTCN3_DIR=/home/titan/titan.core/Install

docker/Dockerfile.ubuntu

@@ -26,7 +26,7 @@ WORKDIR /home/titan/
 RUN git clone https://github.com/eclipse/titan.core.git
 # Checkout release 7.2.1
 WORKDIR /home/titan/titan.core
-RUN git checkout tags/7.2.1
+RUN git checkout tags/7.2.1_final
 
 ## SET Makefile.personal
 # TTCN3_DIR := /home/titan/titan.core/Install