fix typo in javadoc

org.eclipse.debug.core/core/org/eclipse/debug/core/model/ISourceLocator.java

diff --git a/org.eclipse.debug.core/core/org/eclipse/debug/core/model/ISourceLocator.java b/org.eclipse.debug.core/core/org/eclipse/debug/core/model/ISourceLocator.java
index ff1bf1e..0d63e43 100644
--- a/org.eclipse.debug.core/core/org/eclipse/debug/core/model/ISourceLocator.java
+++ b/org.eclipse.debug.core/core/org/eclipse/debug/core/model/ISourceLocator.java
@@ -17,7 +17,7 @@
  * <p>

  * Generally, an implementor of a debug model will also implement launchers

  * and source locators that work together as a whole. That is, the implementation

- * if a source locator will have knowledge of how to locate a source element

+ * of a source locator will have knowledge of how to locate a source element

  * for a stack frame. For example, a Java stack frame could define API which

  * specifies a source file name. A Java source locator would use this information

  * to locate the associated file in the workspace.