remove further unused singleton

Author: SeeSharpSoft

src/main/java/net/seesharpsoft/intellij/plugins/csv/psi/CsvPsiReferenceContributor.java

@@ -2,17 +2,13 @@
 
 import com.intellij.patterns.PlatformPatterns;
 import com.intellij.psi.PsiReferenceContributor;
-import com.intellij.psi.PsiReferenceProvider;
 import com.intellij.psi.PsiReferenceRegistrar;
 import com.intellij.psi.impl.source.resolve.reference.ArbitraryPlaceUrlReferenceProvider;
 import org.jetbrains.annotations.NotNull;
 
 public class CsvPsiReferenceContributor extends PsiReferenceContributor {
-
-    private static PsiReferenceProvider CSV_URL_REFERENCE_PROVIDER_SINGLETON = new ArbitraryPlaceUrlReferenceProvider();
-
     @Override
     public void registerReferenceProviders(@NotNull PsiReferenceRegistrar registrar) {
-        registrar.registerReferenceProvider(PlatformPatterns.psiFile(CsvFile.class), CSV_URL_REFERENCE_PROVIDER_SINGLETON, PsiReferenceRegistrar.LOWER_PRIORITY);
+        registrar.registerReferenceProvider(PlatformPatterns.psiFile(CsvFile.class), new ArbitraryPlaceUrlReferenceProvider(), PsiReferenceRegistrar.LOWER_PRIORITY);
     }
 }