Update Datok for fixed version

Change-Id: I5bb5609fd1581c02266c0f57fdd18f16c247d828
diff --git a/Dockerfile b/Dockerfile
index 38309b0..f63d0f7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -246,10 +246,10 @@
 # Install Datok #
 #################
 
-RUN wget https://github.com/KorAP/Datok/archive/refs/tags/v0.1.1.zip && \
-    unzip v0.1.1.zip && \
-    rm v0.1.1.zip && \
-    mv Datok-0.1.1 Datok && \
+RUN wget https://github.com/KorAP/Datok/archive/refs/tags/v0.1.5.zip && \
+    unzip v0.1.5.zip && \
+    rm v0.1.5.zip && \
+    mv Datok-0.1.5 Datok && \
     cd Datok && \
     go build ./cmd/datok.go