Revert "[test.common_string] disable test for clang"

This reverts commit 3b81976f77a47bdf06189c7ddf0184b7001c6e45.

dune/stuff/test/common_string.cc

@@ -166,8 +166,8 @@ TEST(StringTest, ConvertFrom)
 // Hex, whitespacify, tokenize, stringFromTime tests
 TEST(StringTest, Hex)
 {
-// disabled the following test for Intel anc clang compiler because it causes compilation failures for no obvious reason
-#if !(defined __INTEL_COMPILER || BOOST_CLANG)
+// disabled the following test for Intel compiler because it causes compilation failures for no obvious reason
+#ifndef __INTEL_COMPILER
   EXPECT_GT(boost::lexical_cast<HexToString<unsigned long>>(cout), 0u);
 #endif
   EXPECT_EQ(boost::lexical_cast<HexToString<unsigned long>>("0x00000F"), 15u);