remove SPEC constant in gemspec

This broke `bundle show` if you tried to show soap4r's location with bundler. I suspect this was an older style of creating gemspec files since that line in particular annotates back to ~2006

Resolves issue #10

Author: tjarratt

soap4r.gemspec

@@ -2,7 +2,7 @@
 # Walter Korman ([email protected])
 
 require 'rubygems'
-SPEC = Gem::Specification.new do |s|
+Gem::Specification.new do |s|
   s.name = "soap4r"
   s.version = "1.5.8"
   s.date = "2007-09-24"