minor change

Author: rajithv

lib/symengine/complex.rb

@@ -1,7 +1,7 @@
 module SymEngine
   class Complex
     def to_c
-        to_s.tr('I', 'i').tr('*','').tr(' ','').to_c
+        to_s.tr('I', 'i').delete(' *').to_c
     end
   end
 end