Bug 20556: Move to pt-BR for Portuguese

It seems our translators are only doing pt-BR while we are fetching
pt-PT strings from Mozilla and ship our portuguese bundles as pt-PT ones.
We should move to pt-BR ones instead.

gitian/versions

 TORBROWSER_VERSION_TYPE=release
-BUNDLE_LOCALES="ar de es-ES fa fr it ko nl pl pt-PT ru tr vi zh-CN"
+BUNDLE_LOCALES="ar de es-ES fa fr it ko nl pl pt-BR ru tr vi zh-CN"
 BUNDLE_LOCALES_LINUX="ja"
 BUNDLE_LOCALES_WIN32="ja"
 BUNDLE_LOCALES_MAC="ja-JP-mac"

gitian/versions.alpha

 TORBROWSER_VERSION_TYPE=alpha
-BUNDLE_LOCALES="ar de es-ES fa fr it ko nl pl pt-PT ru tr vi zh-CN"
+BUNDLE_LOCALES="ar de es-ES fa fr it ko nl pl pt-BR ru tr vi zh-CN"
 BUNDLE_LOCALES_LINUX="ja"
 BUNDLE_LOCALES_WIN32="ja"
 BUNDLE_LOCALES_MAC="ja-JP-mac"

gitian/versions.beta

 TORBROWSER_VERSION_TYPE=beta
-BUNDLE_LOCALES="ar de es-ES fa fr it ko nl pl pt-PT ru tr vi zh-CN"
+BUNDLE_LOCALES="ar de es-ES fa fr it ko nl pl pt-BR ru tr vi zh-CN"
 BUNDLE_LOCALES_LINUX="ja"
 BUNDLE_LOCALES_WIN32="ja"
 BUNDLE_LOCALES_MAC="ja-JP-mac"