Fixing language environment variables in stage2 dockerfile

Change-Id: I7332799da5f4d96ad09156bae2f1814552be0d1b
Signed-off-by: sousaedu <eduardo.sousa@canonical.com>
diff --git a/Dockerfile b/Dockerfile
index 3fad212..8230f42 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -34,3 +34,6 @@
 
 RUN python3 -m easy_install pip==21.0.1
 RUN pip3 install tox==3.22.0
+
+ENV LC_ALL C.UTF-8
+ENV LANG C.UTF-8