Fix regex for detecting misspelled library.properties

The previous paucity of parentheses resulted in the regular expression matching against filenames it was never intended
to, resulting in false positives for things like "library.json".

Author: per1234

Diff for: check/checkfunctions/library.go

@@ -60,7 +60,7 @@ func MisspelledLibraryPropertiesFileName() (result checkresult.Type, output stri
 	}
 	directoryListing.FilterOutDirs()
 
-	path, found := containsMisspelledPathBaseName(directoryListing, "library.properties", "(?i)^librar(y)|(ie)s?[.-_]?propert(y)|(ie)s?$")
+	path, found := containsMisspelledPathBaseName(directoryListing, "library.properties", "(?i)^librar((y)|(ie))s?[.-_]?propert((y)|(ie))s?$")
 	if found {
 		return checkresult.Fail, path.String()
 	}