fixed a warning about a mission serializeVersionUID.

However, should this really be serializable at all ?

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@786883 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/math/analysis/solvers/UnivariateRealSolverImpl.java

@@ -31,6 +31,9 @@ import org.apache.commons.math.analysis.UnivariateRealFunction;
 public abstract class UnivariateRealSolverImpl
     extends ConvergingAlgorithmImpl implements UnivariateRealSolver {
 
+    /** Serializable version ID. */
+    private static final long serialVersionUID = 1L;
+
     /** Maximum error of function. */
     protected double functionValueAccuracy;