remove unused localization strings

Emby.Server.Implementations/Localization/Core/en-US.json

@@ -1,5 +1,4 @@
 {
-  "DbUpgradeMessage": "Please wait while your Emby Server database is upgraded. {0}% complete.",
   "AppDeviceValues": "App: {0}, Device: {1}",
   "UserDownloadingItemWithValues": "{0} is downloading {1}",
   "FolderTypeMixed": "Mixed content",
@@ -13,15 +12,12 @@
   "FolderTypeBooks": "Books",
   "FolderTypeTvShows": "TV",
   "FolderTypeInherit": "Inherit",
-  "HeaderCastCrew": "Cast & Crew",
-  "HeaderPeople": "People",
   "ValueSpecialEpisodeName": "Special - {0}",
   "LabelChapterName": "Chapter {0}",
   "NameSeasonUnknown": "Season Unknown",
   "NameSeasonNumber": "Season {0}",
   "LabelExit": "Exit",
   "LabelVisitCommunity": "Visit Community",
-  "LabelGithub": "Github",
   "LabelApiDocumentation": "Api Documentation",
   "LabelDeveloperResources": "Developer Resources",
   "LabelBrowseLibrary": "Browse Library",
@@ -164,15 +160,5 @@
   "HeaderStatus": "Status",
   "HeaderTracks": "Tracks",
   "HeaderMusicArtist": "Music artist",
-  "HeaderLocked": "Locked",
-  "HeaderStudios": "Studios",
-  "HeaderActor": "Actors",
-  "HeaderComposer": "Composers",
-  "HeaderDirector": "Directors",
-  "HeaderGuestStar": "Guest star",
-  "HeaderProducer": "Producers",
-  "HeaderWriter": "Writers",
-  "HeaderParentalRatings": "Parental Ratings",
-  "HeaderCommunityRatings": "Community ratings",
   "StartupEmbyServerIsLoading": "Emby Server is loading. Please try again shortly."
 }