support/testing: test_gstreamer1: raise tesseract-ocr timeout to 15s

On my laptop (i5-8365U), running cross-tesseract-ocr in QEMU takes
longer than the default timeout (5s), causing the test to fail:

 # time tesseract frame10.png output
 Error in pixReadMemTiff: function not present
 Error in pixReadMem: tiff: no pix returned
 Error in pixaGenerateFontFromString: pix not made
 Error in bmfCreate: font pixa not made
 Estimating resolution as 157
 real    0m 8.17s
 user    0m 5.36s
 sys     0m 2.79s

So extend the assertRunOk() timeout with ~2x that similar to how it is done
for the gst-launch-1.0 pipeline.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>

support/testing/tests/package/test_gstreamer1.py

@@ -75,7 +75,7 @@ class TestGstreamer1(infra.basetest.BRTest):
         # We extract the text from our last image.
         img_file = f"frame{num_frames}.png"
         cmd = f"tesseract {img_file} output"
-        self.assertRunOk(cmd)
+        self.assertRunOk(cmd, timeout=15)
 
         # We check we have our initial message.
         out, ret = self.emulator.run("cat output.txt")