Fix another bunch of warnings

src/algebra/EigenvalueSolverOptions.hpp

@@ -61,11 +61,6 @@ class EigenvalueSolverOptions
  private:
   ESLibrary m_library = ESLibrary::slepsc;
 
-  double m_epsilon           = 1E-6;
-  size_t m_maximum_iteration = 200;
-
-  bool m_verbose = false;
-
  public:
   static EigenvalueSolverOptions default_options;
 
@@ -83,18 +78,6 @@ class EigenvalueSolverOptions
     return m_library;
   }
 
-  bool&
-  verbose()
-  {
-    return m_verbose;
-  };
-
-  bool
-  verbose() const
-  {
-    return m_verbose;
-  };
-
   EigenvalueSolverOptions(const EigenvalueSolverOptions&) = default;
   EigenvalueSolverOptions(EigenvalueSolverOptions&&)      = default;