improvements supplier translations

app/models/section.rb

@@ -77,6 +77,7 @@ class Section
     w = width
     h = height
     n = tables.size
+    return unless w > 0 && h > 0 && n > 0
     l = Math.sqrt((w*h).to_f/n)
     epsilon = (10 ** -(Float::DIG - 1)).to_f
     while (w/l).floor * (h/l).floor < n # find a fitting combination

app/models/supplier.rb

@@ -83,7 +83,7 @@ class Supplier
   private
 
   def add_section_on_create
-    @section = Section.create supplier: self, title: I18n.t('section.first_section_title')
+    @section = Section.create supplier: self, title: I18n.t('supplier.section.first_section_title')
   end
 
 end