Use a different random seed for solverMLE example

Otherwise, the build fails with a division by zero error.

M2/Macaulay2/packages/GraphicalModelsMLE.m2

@@ -1486,6 +1486,7 @@ doc ///
      This optional input only applies when the sample data or the sample covariance matrix has real entries.
      By default, the precision is 53 (the default precision for real numbers in M2).
     Example
+     setRandomSeed 1
      G = mixedGraph(digraph {{1,2},{1,3},{2,3},{3,4}},bigraph {{3,4}});
      U = matrix{{6.2849049, 10.292875, 1.038475, 1.1845757}, {3.1938475, 3.2573, 1.13847, 1}, {4/5, 3/2, 9/8, 3/10}, {10/7, 2/3,1, 8/3}};
      solverMLE(G,U,RealPrecision=>10)