Require 10 words for language detection

app/src/main/java/eu/faircode/email/TextHelper.java

@@ -60,6 +60,7 @@ import javax.xml.transform.stream.StreamResult;
 import javax.xml.transform.stream.StreamSource;
 
 public class TextHelper {
+    private static final int MIN_WORDS = 10;
     private static final int MAX_DETECT_SAMPLE_SIZE = 8192;
     private static final float MIN_DETECT_PROBABILITY = 0.80f;
     private static final String TRANSLITERATOR = "Any-Latin; Latin-ASCII";
@@ -82,6 +83,9 @@ public class TextHelper {
         if (TextUtils.isEmpty(text))
             return null;
 
+        if (text.split("\\s+").length < MIN_WORDS)
+            return null;
+
         byte[] octets = text.getBytes();
         byte[] sample;
         if (octets.length < MAX_DETECT_SAMPLE_SIZE)