Do not handle single keys as numbers

This is a workaround when a session keyword is entered as a single key

src/main/java/de/thm/arsnova/dao/NovaView.java

@@ -98,9 +98,6 @@ public class NovaView extends View {
 	}
 
 	private String quote(String string) {
-		if (isNumber(string)) {
-			return encode(string);
-		}
 		return encode("\"" + string + "\"");
 	}
 	

src/test/java/de/thm/arsnova/dao/NovaViewTest.java

@@ -97,13 +97,6 @@ public class NovaViewTest {
 		assertEncodedEquals("key", "[\"foo\",\"bar\",2]", v.getQueryString());
 	}
 
-	@Test
-	public void singleKeysShouldNotEnquoteNumbers() {
-		NovaView v = new NovaView(null);
-		v.setKey("2");
-		assertEncodedEquals("key", "2", v.getQueryString());
-	}
-
 	@Test
 	public void singleArrayKeysShouldNotEnquoteNumbers() {
 		NovaView v1 = new NovaView(null);