Check if sydent was installed

src/freedombone-app-matrix

     systemctl restart nginx
     systemctl restart turn
     systemctl restart matrix
-    systemctl restart sydent
+    if [ -f /etc/systemd/system/sydent.service ]; then
+        systemctl restart sydent
+    fi
 
     # wait for nginx to start otherwise user add fails later
     sleep 5
     firewall_remove ${MATRIX_HTTP_PORT}
 
     systemctl stop matrix
-    systemctl stop sydent
+    if [ -f /etc/systemd/system/sydent.service ]; then
+        systemctl stop sydent
+    fi
 
     function_check remove_turn
     remove_turn
 
     systemctl disable matrix
-    systemctl disable sydent
-    if [ -f /etc/systemd/system/matrix.service ]; then
-        rm /etc/systemd/system/matrix.service
-    fi
     if [ -f /etc/systemd/system/sydent.service ]; then
+        systemctl disable sydent
         rm /etc/systemd/system/sydent.service
     fi
+    if [ -f /etc/systemd/system/matrix.service ]; then
+        rm /etc/systemd/system/matrix.service
+    fi
     apt-get -y remove --purge coturn
     cd /etc/matrix
     pip uninstall .
-    cd /etc/sydent
-    pip uninstall .
+    if [ -d /etc/sydent ]; then
+        cd /etc/sydent
+        pip uninstall .
+        rm -rf /etc/sydent
+    fi
     rm -rf $MATRIX_DATA_DIR
     rm -rf /etc/matrix
-    rm -rf /etc/sydent
     deluser matrix
     delgroup matrix
     remove_onion_service matrix ${MATRIX_ONION_PORT}