adding more than 4 channels random Mats support

if `Scalar:all` is used, Mats with 5+ channels cause errors

modules/ts/src/ts_func.cpp

@@ -116,7 +116,7 @@ Mat randomMat(RNG& rng, Size size, int type, double minVal, double maxVal, bool
 
     Mat m(size0, type);
 
-    rng.fill(m, RNG::UNIFORM, Scalar::all(minVal), Scalar::all(maxVal));
+    rng.fill(m, RNG::UNIFORM, minVal, maxVal);
     if( size0 == size )
         return m;
     return m(Rect((size0.width-size.width)/2, (size0.height-size.height)/2, size.width, size.height));
@@ -142,7 +142,7 @@ Mat randomMat(RNG& rng, const vector<int>& size, int type, double minVal, double
 
     Mat m(dims, &size0[0], type);
 
-    rng.fill(m, RNG::UNIFORM, Scalar::all(minVal), Scalar::all(maxVal));
+    rng.fill(m, RNG::UNIFORM, minVal, maxVal);
     if( eqsize )
         return m;
     return m(&r[0]);