Fix some warnings on gcc 11

src/PrusaSlicer.cpp

@@ -705,7 +705,7 @@ bool CLI::setup(int argc, char **argv)
 
     // Initialize with defaults.
     for (const t_optiondef_map *options : { &cli_actions_config_def.options, &cli_transform_config_def.options, &cli_misc_config_def.options })
-        for (const std::pair<t_config_option_key, ConfigOptionDef> &optdef : *options)
+        for (const t_optiondef_map::value_type &optdef : *options)
             m_config.option(optdef.first, true);
 
     set_data_dir(m_config.opt_string("datadir"));

src/libnest2d/include/libnest2d/placers/nfpplacer.hpp

@@ -577,7 +577,7 @@ private:
 
 
     template<class Level>
-    Shapes calcnfp(const Item &trsh, Level)
+    Shapes calcnfp(const Item &/*trsh*/, Level)
     { // Function for arbitrary level of nfp implementation
 
         // TODO: implement

src/libnest2d/include/libnest2d/placers/placer_boilerplate.hpp

@@ -33,7 +33,8 @@ public:
         PackResult(Item& item):
             item_ptr_(&item),
             move_(item.translation()),
-            rot_(item.rotation()) {}
+            rot_(item.rotation()),
+            overfit_(1.0) {}
 
         PackResult(double overfit = 1.0):
             item_ptr_(nullptr), overfit_(overfit) {}