Fix typo in 'pi()'

glm/ext/scalar_constants.inl

@@ -12,7 +12,7 @@ namespace glm
 	template<typename genType>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR genType pi()
 	{
-		GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559, "'epsilon' only accepts floating-point inputs");
+		GLM_STATIC_ASSERT(std::numeric_limits<genType>::is_iec559, "'pi' only accepts floating-point inputs");
 		return static_cast<genType>(3.14159265358979323846264338327950288);
 	}
 } //namespace glm