Change gaussianBlur5x5 perf test epsilon

Set it 1 instead of 0.001, as is already done in gaussianBlur3x3. That
will allow integer destination matrices that are not exactly the same,
but very close to the expected result, to pass the test.

modules/imgproc/perf/perf_blur.cpp

@@ -183,7 +183,7 @@ PERF_TEST_P(Size_MatType_BorderType, gaussianBlur5x5,
 
     TEST_CYCLE() GaussianBlur(src, dst, Size(5,5), 0, 0, btype);
 
-    SANITY_CHECK(dst, 1e-3);
+    SANITY_CHECK(dst, 1);
 }
 
 PERF_TEST_P(Size_MatType_BorderType, blur5x5,