Update taiga backend version

Dockerfile

@@ -17,7 +17,7 @@ RUN apt-get update && apt-get install -y \
 # https://github.com/taigaio/taiga-back/tree/stable
 
 ## backend
-RUN curl -L https://github.com/taigaio/taiga-back/archive/e75510507c22d5938b6f9b19b554483e4390ccd8.tar.gz | tar -xz -C /app/code/taiga-back --strip-components 1 -f -
+RUN curl -L https://github.com/taigaio/taiga-back/archive/61c06538986bf236ba6d0b6bb3ca19a64ad329bb.tar.gz | tar -xz -C /app/code/taiga-back --strip-components 1 -f -
 
 ## frontend
 RUN curl -L https://github.com/taigaio/taiga-front-dist/archive/93bbd82a983d3f7f694bfe3d460221d6ae6701ba.tar.gz | tar -xz -C /app/code/taiga-front-dist --strip-components 1 -f -