This error is due to the absence of pecl_http extension in php.

You can easily install it on Linux server using pecl or pear command.

# pecl install pecl_http

If you have any problem/error while installing it using pecl command then you can do it manually , please follow the steps
1) Download the pecl_http source file

Quote:
wget http://pecl.php.net/get/pecl_http-1.6.1.tgz
2) uncompress the file
Quote:
tar –xzvf pecl_http-1.6.1.tgz
cd pecl_http-*
3) compile and install
Quote:
# phpize
# ./configure
#make
#make install
4) Once it done you will have add “extension=http.so” line to php.ini file.
5) Restart apache.