Update from Leptonica 1.74.1 to 1.74.2

The newer version contains fixes for the pixUnsharpMaskingGray*
functions which are relevant for Tesseract (used in ImageData::PreScale
which calls pixScale).
Signed-off-by: NStefan Weil <sw@weilnetz.de>

.travis.yml

@@ -5,7 +5,7 @@ language: cpp
 dist: trusty
 
 env:
-  - LEPT_VER=1.74.1
+  - LEPT_VER=1.74.2
 
 notifications:
   email: false

snap/snapcraft.yaml

@@ -30,5 +30,5 @@ parts:
       - libcairo2-dev
     after: [leptonica]
   leptonica:
-    source: http://www.leptonica.org/source/leptonica-1.74.1.tar.gz
+    source: http://www.leptonica.org/source/leptonica-1.74.2.tar.gz
     plugin: autotools