Changed the optional message to be more clear

src/strings/en-GB.json

@@ -82,7 +82,7 @@
   "LabelUrl": "URL:",
   "LabelZipCode": "Post Code:",
   "LabelffmpegPathHelp": "The path to the ffmpeg application file or folder containing ffmpeg.",
-  "LeaveBlankToNotSetAPassword": "This field can be left blank.",
+  "LeaveBlankToNotSetAPassword": "Optional - leave blank to set no password",
   "LinkApi": "API",
   "MessageConfirmRevokeApiKey": "Are you sure you wish to revoke this API key? The application's connection to Jellyfin Server will be abruptly terminated.",
   "MessageForgotPasswordFileExpiration": "The reset PIN will expire at {0}.",

src/strings/en-US.json

@@ -1028,7 +1028,7 @@
   "LanNetworksHelp": "Comma separated list of IP addresses or IP/netmask entries for networks that will be considered on local network when enforcing bandwidth restrictions. If set, all other IP addresses will be considered to be on the external network and will be subject to the external bandwidth restrictions. If left blank, only the server's subnet is considered to be on the local network.",
   "LatestFromLibrary": "Latest {0}",
   "LearnHowToCreateSynologyShares": "Learn how to share folders in Synology.",
-  "LeaveBlankToNotSetAPassword": "This field can be left blank.",
+  "LeaveBlankToNotSetAPassword": "Optional - leave blank to set no password",
   "LetterButtonAbbreviation": "A",
   "LibraryAccessHelp": "Select the media folders to share with this user. Administrators will be able to edit all folders using the metadata manager.",
   "LinkApi": "Api",