Modify tests for text wrongly split into encoded words

We were using test data submitted by users. But we don't really know
what the expected result should be. In the second test the expected text
ended in a replacement character. That indicates the text is not decoded
correctly. Maybe there was an additional encoded word that was missing.

k9mail-library/src/test/java/com/fsck/k9/mail/internet/DecoderUtilTest.java

@@ -114,17 +114,10 @@ public class DecoderUtilTest {
 
     @Test
     public void decodeEncodedWords_withMultipleEncodedSections_decodesSequentialSectionTogether() {
-        //Splitting mid-character is RFC2047 non-compliant but seen in practice.
-        String input = "=?utf-8?B?5Liq5Lq66YKu566xOkJVRyAjMzAyNDY6OumCruS7tuato+aWh+mZhOS7tuWQ?=\n" +
-                "=?utf-8?B?jeensOecgeeVpeaYvuekuuS8mOWMlg==?=";
-        assertInputDecodesToExpected(input, "个人邮箱:BUG #30246::邮件正文附件名称省略显示优化");
-    }
-
-    @Test
-    public void decodeEncodedWords_withGB2312_decodes_correctly() {
-        String input = "=?gb2312?B?Obv9t9az6cnu29rHsLqju6rHyLPHSlfN8rrAvsa16qOsuPzT0DIwvNIzOTnU?= " +
-                "=?gb2312?B?qr6r0aG439DHytTLr77Gteq1yMTjwLSjoaOoQUSjqQ?=";
-        assertInputDecodesToExpected(input, "9积分抽深圳前海华侨城JW万豪酒店，更有20家399元精选高星试睡酒店等你来！（AD<EFBFBD>");
+        // Splitting mid-character is RFC2047 non-compliant but seen in practice.
+        // "=?utf-8?B?b2hhaSDw?=" individually decodes to "ohai <20>"
+        // "=?utf-8?B?n5Kp==?=" individually decodes to "<EFBFBD><EFBFBD><EFBFBD>"
+        assertInputDecodesToExpected("=?utf-8?B?b2hhaSDw?= =?utf-8?B?n5Kp?=", "ohai 💩");
     }
 
     @Test