Re-order sed command to fix new pad title

pica-etherpad/Dockerfile

@@ -40,11 +40,11 @@ RUN curl -SL https://github.com/ether/etherpad-lite/archive/${ETHERPAD_VERSION_B
     git --git-dir=src/templates/picasoft-etherpad-landing-page/.git checkout ${ETHERPAD_LANDING_PAGE_VERSION_BUILD} && \
     cp src/templates/picasoft-etherpad-landing-page/index.html src/templates/index.html && \
     cp src/templates/picasoft-etherpad-landing-page/static/* src/static/ -r && \
-    # Change default hard-coded pad title
-    sed -i 's|Untitled Pad|Nouveau pad|g' node_modules/ep_set_title_on_pad/templates/title.ejs && \
-    sed -i 's|Untitled Pad|Nouveau pad|g' node_modules/ep_set_title_on_pad/static/tests/frontend/specs/atest.js
 
-RUN for PLUGIN_NAME in ${ETHERPAD_PLUGINS}; do npm install "${PLUGIN_NAME}"; done
+RUN for PLUGIN_NAME in ${ETHERPAD_PLUGINS}; do npm install "${PLUGIN_NAME}"; done && \
+  # Change default hard-coded pad title
+  sed -i 's|Untitled Pad|Nouveau pad|g' node_modules/ep_set_title_on_pad/templates/title.ejs && \
+  sed -i 's|Untitled Pad|Nouveau pad|g' node_modules/ep_set_title_on_pad/static/tests/frontend/specs/atest.js
 
 # construction de l'image finale
 FROM base