Fixes a bug that would prevent replacing multiple placeholders in a single string

Example string in .po file:

msgid: "EXAMPLE_ID“
msgstr: "This is a sample with not {replace_one}, not {replace_two}, but {replace_three} placeholders“

OLD: Would be incorrectly parsed, therefore only {replace_one} is handled by angular-translate
NEW: Fixes incorrect parsing, so that all three placeholders in the above example may be handled by angular-translate