DOC: OTB_CONFIG_FILE is used for environment search

Code/Common/otbConfigurationFile.cxx

@@ -35,7 +35,7 @@ ConfigurationFile
     if (!itksys::SystemTools::FileExists(envVar, true))
       {
       itkWarningMacro(<< "When loading the OTB configuration file, "
-                         "the OTB_CONFIG env. var was found, but points a non-existant file : "
+                         "the OTB_CONFIG_FILE env. var was found, but points a non-existant file : "
                       << envVar);
       }
     else

Code/Common/otbConfigurationFile.h

@@ -31,7 +31,7 @@ namespace otb
 /** \class ConfigurationFile
  *  \brief Manage OTB ConfigurationFile file
  *
- *  The path to the file can be set with environment variable OTB_CONFIG
+ *  The path to the file can be set with environment variable OTB_CONFIG_FILE
  *
 */