[rubygems/rubygems] Move security exception handling to the only place using it

https://github.com/rubygems/rubygems/commit/ba975b3b7f

lib/bundler/rubygems_integration.rb

@@ -205,10 +205,6 @@ module Bundler
 
     def spec_from_gem(path, policy = nil)
       gem_from_path(path, security_policies[policy]).spec
-    rescue Gem::Security::Exception => e
-      raise SecurityError,
-        "The gem #{File.basename(path, ".gem")} can't be installed because " \
-        "the security policy didn't allow it, with the message: #{e.message}"
     end
 
     def build_gem(gem_dir, spec)

lib/bundler/source/rubygems.rb

@@ -157,6 +157,10 @@ module Bundler
           path = fetch_gem(spec, options[:previous_spec])
           begin
             s = Bundler.rubygems.spec_from_gem(path, Bundler.settings["trust-policy"])
+          rescue Gem::Security::Exception => e
+            raise SecurityError,
+              "The gem #{File.basename(path, ".gem")} can't be installed because " \
+              "the security policy didn't allow it, with the message: #{e.message}"
           rescue Gem::Package::FormatError
             Bundler.rm_rf(path)
             raise