Max stamina modifiers from mutations now affect stamina regen (#39994)

src/character.cpp

@@ -7423,8 +7423,9 @@ void Character::update_stamina( int turns )
     float stamina_recovery = 0.0f;
     // Recover some stamina every turn.
     // Mutated stamina works even when winded
+    // max stamina modifers from mutation also affect stamina multi
     float stamina_multiplier = ( !has_effect( effect_winded ) ? 1.0f : 0.1f ) +
-                               mutation_value( stamina_regen_modifier );
+                               mutation_value( stamina_regen_modifier ) + ( mutation_value( "max_stamina_modifier" ) - 1.0f );
     // But mouth encumbrance interferes, even with mutated stamina.
     stamina_recovery += stamina_multiplier * std::max( 1.0f,
                         base_regen_rate - ( encumb( bp_mouth ) / 5.0f ) );