[arabic_high_hamza] Make the size of high hamza a warning

It seems to be debatable since high hamza is used also in Kazakh where
small high hamza is acceptable. Instead of complicated and possibly
error prune language detection, lets make it a warning.

Author: khaledhosny

Lib/fontbakery/checks/arabic_high_hamza.py

@@ -1,4 +1,4 @@
-from fontbakery.prelude import FAIL, SKIP, Message, check
+from fontbakery.prelude import FAIL, SKIP, WARN, Message, check
 from fontbakery.utils import get_glyph_name
 
 
@@ -70,9 +70,9 @@ def check_arabic_high_hamza(ttFont):
     high_hamza_area = area_pen.value
 
     if abs((high_hamza_area - hamza_area) / hamza_area) > 0.1:
-        yield FAIL, Message(
+        yield WARN, Message(
             "glyph-area",
             "The arabic letter high hamza (U+0674) should have roughly"
-            " the same size the arabic letter hamza (U+0621),"
-            " but a different glyph outline area was detected.",
+            " the same size the arabic letter hamza (U+0621) while raised"
+            " above baseline, but a different glyph outline area was detected.",
         )