Fixed an error in installation script

Because of the forward slashes in the directory, sed did not work. This
is solved in this commit by replacing the / separators with |.

install.sh

@@ -110,10 +110,10 @@ read -p 'Matrix username: ' username
 read -p 'Matrix password: ' password
 read -p 'Super user: ' superuser
 
-sed -e "s/\${server}/${server}/"\
-    -e "s/\${username}/${username}/"\
-    -e "s/\${password}/${password}/"\
-    -e "s/\${superuser}/${superuser}/"\
+sed -e "s|\${server}|${server}|"\
+    -e "s|\${username}|${username}|"\
+    -e "s|\${password}|${password}|"\
+    -e "s|\${superuser}|${superuser}|"\
     $DIR/config.json.template > $DIR/config.json
 
 #################################################################
@@ -125,7 +125,7 @@ fi
 
 sudo useradd -r mchatbot
 
-sed -e "s/\${DIR}/${DIR}/"\
+sed -e "s|\${DIR}|${DIR}|"\
     $DIR/plugable-matrix-bot.service.template > $DIR/plugable-matrix-bot.service
 
 sudo mv $DIR/plugable-matrix-bot.service /etc/systemd/system/plugable-matrix-bot.service