read iv from chiffre (still not correct but at least less wrong now)

src/test/java/ch/fhnw/kry/CTRTest.java

@@ -8,11 +8,9 @@ class CTRTest {
 
     @Test
     void generateIV() {
-        var ctr = new CTR(0);
-
         int count = 0;
         while(count < Integer.MAX_VALUE) {
-            int iv = ctr.generateIV();
+            int iv = CTR.generateIV();
             assert (iv < 1 << 16);
             count++;
         }