Proof: fixed a typo, and handled the case when the script is running from rootless docker

Change-Id: I6decbad624dfb2aa1b89e28ca9271d5da442507c
Reviewed-on: https://gerrit.libreoffice.org/c/online/+/92864
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Andras Timar <andras.timar@collabora.com>

loolwsd-generate-proof-key

@@ -1,12 +1,14 @@
 #!/bin/bash
 
 SUDO=''
-if (( $EUID != 0 )); then
-    if hash sudo 2>/dev/null; then
-        SUDO='sudo'
-    else
-        "Run the script as root."
-        exit 1
+if [ ! -w "/etc/loolwsd" ]; then
+    if (( $EUID != 0 )); then
+        if hash sudo 2>/dev/null; then
+            SUDO='sudo'
+        else
+            echo "Run the script as root."
+            exit 1
+        fi
     fi
 fi